A Problem Squared - 129 = People off Ground and Pound for Pound

Episode Date: March 2, 2026

🛫 How many people are flying in the air at any given moment?⚖️ What weighs a pound and costs a pound?🏈 And there’s some Any Other (Foot)BallnessHead to our socials to see Bec’s glasses ����Pat Patriot 🇺🇲and our Pound for Pound items!Here is a link to the book Flying With Confidence (which helped Producer Laura with her fear of flying and also helped her answer the problem correctly!)https://www.penguin.co.uk/books/415543/flying-with-confidence-by-patricia-furness-smith-and-captain-steve-allright/9780091947859They Did The Math, They Did The Monster Math on Reddithttps://www.reddit.com/r/theydidthemath/ https://www.reddit.com/r/theydidthemonstermath/Flight Radar 24: https://www.flightradar24.com/If you’d like to see Bec at the Adelaide Fringe, you can get tickets here: https://adelaidefringe.com.au/fringetix/bec-hill-creates-the-perfect-show-work-in-progress-af2026 And if you’d like to see Matt on tour, all the dates, venues and tickets can be found here: http://standupmaths.com/shows Join us on Patreon for early releases and our monthly bonus podcast I’m A Wizard! If you’re already on Patreon and have a creative Wizard offer to give Bec and Matt, please comment on our pinned post!  If you want to (we’re not forcing anyone) please do leave us a review, share the podcast with a friend, or give us a rating! Please do that. It really helps. Finally, if you want even more from A Problem Squared you can connect with us and other listeners on BlueSky, Twitter, Instagram, and on Discord.

Hello and welcome to a problem square, the problem solving podcast that's a bit like a game of American football. Oh. In that there's a lot of stopping and starting, endless diagrams, but it still somehow passes as entertainment. I'm Matt Parker, mathematician performer, and I'm like a nose tackle. Nose tackle. Name of a real position. And that I'm always trying to stop play and slow things down so we can tackle. how do we knows.

Yay! You wrote an actual intro. That's a real joke! That's good. Beck is like the Super Bowl halftime show. A professional and entertainer and bringing a bit of showbiz and pizzazz to the whole production.

And you DJ. On this episode... Oh, you're doing so well. I'm going to see how many people are in the air. I've made some comparisons that are pound for pound. And there'll be some, any other, bowlness.

Ballness? Yeah. Like a ball. In brackets, foot. To Beck, how are you? I'm good. Great. I'm good.

We've recorded, I'm a wizard, our bonus podcast. We did, yes. For March. Finished seconds ago. Yes. And I've been sitting in this room with you and producer Laura for quite some time now. Yeah? And none of you have commented.

Oh, oh. on something that is different about me. Oh, producer Laura's turning her mic on. You've had your hair cup. That's actually not it. I have had a slight hair cup. This is well within the error bars of Beck's hair. Yes, yeah.

True, but you have had your hair. Yes, well spotted. You have new glasses. Yeah. You've got new glasses. Look, and I realize this is an audio medium. So, Matt, you can do scrambling glasses for the audience. This is revenge for all the times I've done that.

Yeah. They're great. They're sitting roughly halfway up Beck's face. Okay. You're going to get it to. Okay. I'm looking at them dead on. They got like kind of an ambery color to them.

They're nice. They're not square. They got a little bit of a taper towards the base. And if Beck looks in one direction to the side. I suppose they're more square than, well, I'll tell you what, they're more square than my second pair of glass. Oh, my goodness. Oh, and the.

sides are like a metallic finish. Great. So. Oh, okay. These ones are different in everything I just said. These are pink on top, business down below. Yeah, that's probably the best description. They're circular now. Yeah. But I suspect if you turn sideways, there's still metal, metal wings. Yes. Oh, yeah, but now a little bit more, little gold. Mm-hmm. And then a little little pink flourish at the end there. Thanks. Two pairs of glasses. Yeah. Turns out it been like two years since I last had my eyes tested. Yeah.

And I needed upgrades. And it's so much better now. Right, you can see things. I mean, I've done other stuff, but... No, this is the highlight. So did you have to go in and get your eyes tested and then... I did? I got my eyes tested.

Oh, a year ago, year or two ago. Maybe I should do it again. My optometrist said, you've got a lot of nerve. Optical nerve. Yeah. Please tell me that is how he said it. No. It was...

It was in that order, but he didn't say it with the optimal funniest phrasing. He was like, oh, wow, that's a lot of nerve. And I'm like, oh, you're so close. You're so close. It was right there. You're right there. And you probably say this so many times each day. I know.

And I was like, don't worry. When I retell the story, I'll punch it up a tad. Well, the last time I got my eyes tested before this time, it was near my birthday. And she, they asked you for your birthday. And she was like, oh, it's your birthday next week. And then she looked at the year and she went, oh, wow, you look amazing. And I was like, oh, thanks. This time I did the eye test.

Gave them my birth date, nothing. So I don't know what. Back in alignment. I don't know what happened in the last two years. I know what happened in the last two years. You aged. Yeah. Sure did. I then found out if you asked the optometrist nicely, he emailed me the scans of my retinas.

Ooh. I haven't done. Because I had so much nerve. And then did you just. try on a rae like a hilarious montage of

trying on pairs of glasses. One of my best friends who I would normally take with me to

the optometrist for her opinion. Yep. I may have mentioned this before. I know I've

said it to you guys off air. She has been since the beginning of the year, stuck at

home with her parents because she broke her leg on the second day by slipping on ice.

So she couldn't come in with me which meant that I spent about an hour and a half

taking photos of me in all of the glasses and then doing a sort of match to the death where I would send her two pairs and be like left or right. That's a good method. Yeah. Inspired by.

Yeah. How they test your eyes. So I got it to do that and then eventually got it down to two pairs. And it was between the pair that I am now back to wearing again, which is the Amberie type pair and a different pair. And she had vetoed the pink pair early on. Oh. But then I said, I'm vetoing your veto.

I was like, I'm going to choose the other ones because I think you haven't seen them in person. I'm so sorry, everyone. What a boring. This is great. Yeah, I now have a bunch of photos of me in different glasses. There you go. But like trying to keep the same non-expressive face. Yeah, yeah, for comparison purposes.

Yeah, and I didn't want her to be like, oh, you look happier in this pair. So I tried to just have a passport photo look. But it does look like I look like a criminal on the run who's trying on different disguises. Now you did bring your own nose and moustache. I'll give them to Laura. She can put them on the Instagram. All I ask is that Laura does not make the photo the first one on the carousel of photos on Instagram because no one needs that. Interesting, interesting.

How about you, Matt? Well, this is the Super Bowl recording. Yes. by which you mean we booked a recording date the day after Super Bowl. We shuffled dates for some reason. I can't remember why. Because I'm about to go away for two and a half months. Yeah, that's probably it.

And we're like, huh, well, one of the only days we can make this work is this today, this Monday. And I was like, well, we can do that. But in my diary it says, Matt, don't do any work today for it is the day after Super Bowl. And I'm not a big American football kind of gay, but I do enjoy a good. bandwagoning sport experience. You're like me with Eurovision. I'm not shooting in for the semis. No,

watch the finals. Yeah, exactly. Yeah. And I was like, I'm all set. I'm going to stay up. I got my red solar cups. I'm going to stay up and watch the big game.

Yep. Which I did. But it meant I got to bed very late, which is why if I sound. All the windows are open. Yeah. A lot of cheap beer was consumed. And it wasn't even a particularly exciting game.

First of all, I didn't... Who was playing? So it was the Seattle Seahawks. Okay. Against the New England Patriots. Cool. Those are words? Yep, New England, not a place.

It was a region. Oh. I know. How's that work? Their mascot is just a Caucasian guy. You're kidding. It's so stupid. That's a joke, surely?

That's not a joke. What are? Look it up. At least the Seahawks have a hawk. That's such a funny. Like, to be like, the Patriots, they're like, I was. just a Caucasian guy. Yeah. Yeah. He's so funny.

He's called Pat. He's called Pat. Pat Patriot. Wait, but surely like Pat Riot would be a better name. Riot is a cooler surname. Plus then it's Patriot. Yeah.

But they've called him Pat. And then the whole word again, Patriot. Got New England Patriot. Get your shins together. I mean, to be honest, of all of the logos of American football teams, Not the most problematic. No, no. There's some pretty serious competition on that one. I'll give you that, Pat.

Yeah. Pat Riot does sound like a drag act. And looking at the logo, it looks like a drag act. It can work, yep. There's a very good drag act in this. And it could either be a drag queen or a drag king, and it would still work. Let's do it. All right, I'm announcing it here.

At some point, I am going to do my drag king character, Pat Wright. I'm going to have a wig. that's got a big white star on it. It goes from Navy to red. I'm not going to look up any facts about football, but I will talk about football. Great. Or the Revolutionary War.

It just goes straight into it. Right, done. Sold. I've been trying to work out what to put in my show for Adelaide Fringe. Now, there, yes. People go see Beck at the Adelaide Fringe. Pat Riot. Two for one.

You also get to see Pat Riot. Yeah. Yeah, so I got to watch that. But the game wasn't particularly exciting. It was a pretty low-scoring game. It looked like, for the first time in Super Bowl history, one of the teams would not score a single point. The first three quarters, Pat's team, zero points. Wow.

They were, it wasn't going well. That's embarrassing for that. And I found it very funny, as well as being very distracted by their Caucasian male. That's the mascot. Just a guy. Their quarterback. who I know everyone at this level is an incredibly skilled athlete and they've done phenomenal things to be there.

He was the second youngest quarterback in a Super Bowl at about, I think, 24, but just looked so young and just looked comically young next to these massive older players. And is all the gear like making them look like a child in his dad's suit? Yeah, 100%. I was like, I feel like I'm watching a dad's suit. watching a Disney film where a kid made a wish. But then the highlight, they did eventually do a do a touchdown and get the conversion point.

And they brought the score up to be 227, which is an approximation of pie. Great. And so I had a wonderful moment. I was like, this is why I didn't go to bed before the fourth quarter. This is why I stick with the game. So maybe it's boring. So maybe you feel like this is a subpar episode. Matt says it's worth it?

Yeah. And I'll be honest, it's not like I've made up for it with my glasses chat. Glasses chat. Good stuff. Shall we keep this high standard rolling? Let's play ball. Let's play ball. Let's play football.

Our first problem was sent in by Greg, who went to the problem posing page at a problem square.com. And they typed in to the mighty Matt and Beck. Correct. Which could also be read to the mighty Matt and Beck. There's no Oxford comma. I'm in on this. Oh, fine, fine, fine.

This is a shared mightiness. Okay, to the mighties, Matt and Beck. Greg says they are a frequent business traveler, and when they're bored on airline flights, they start to wonder how much of the world's population is in the air at any moment. Given the fact planes are up almost constantly, I could see it, this is Greg's voice now, I could see it being large,

but there's also an astonishing amount of us. That's deep Greg. And they're not just talking about Gregs. I love the podcast, blah, blah, blah. Right, so Beck, you're going to put some entertainment into Greg's life here. Yeah. Now I want to know how many Gregs could be in the air. How many Gregs are in the air at any one point?

We'll see if we can figure that out. We can multiply the answer by the rate of Gregness. I looked into this. But do you have a rough, without thinking too hard, do you have like a rough, a rough idea of what you think the correct answer might be. Oh, yikes. Ballpark. I have a rough.

Well done. Yeah. I have a sense of how I might do it. I'd be like... That's not what I've asked. I've said, just throw it out there. What number feels right? Oh, okay.

So let's say there's a couple hundred people on a plane. Plan's every five minutes. No, don't want to hear you working out. What's your answer? Oh, I got to... Okay. The answer is... He's working out.

Matt, just say your number. It's hundreds of thousands. Hundreds of thousands. Hundreds of thousands. Like the thing you put on fairy bread. You're that hundreds. No, it's hundreds and thousands. Oh, that's true.

Little reference for the Aussies there. There you go. I've always wanted to count a pack of hundreds and thousands and answer the question once and for all. Well, you could. Because it's hundreds or thousands. Here's the news, Matt. No one's stopping you.

In fact, you could write in to the problem closing page. No one write in. Okay. So let's say 300,000. Okay. Laura? So I really hate flying. Oh, so sorry.

Subtract one. Oh, yeah. Don't count me. But I read a really, really good self-help book called Flying with Confidence, which is co-written by a psychologist and a former British Airways pilot. And it's all about like the mechanics of how planes work. And it's really reassuring. So it genuinely helped.

I read that and get that audio book. better. Yeah, yeah, it calms me down. But in that, as a reassuring stat about how safe flying is, there is a line that says at any given second there are a million people in the air. Hang on. Is that cheating just by knowing the answer? Well, I don't know if I know the answer, and I haven't checked it, but it's a reassuring thing because, hey, it's really safe because there's a million people in the air all the time. Also, when did the book come out? 2013. 2013. I know as well as anyone, the kind of slap dash research. They can, end up in a published book.

Yeah, exactly. They're not checking their sources. No one's checking. So I looked it up. It does appear that there is like an answer that most people. Now, obviously what you want to do is do the maths. Oh, yeah, but you're not allowed to apparently. Well, I'm not allowed.

No, I could. I could do the maths, but other people have done it for me. Oh, great, great. So I wanted to ask you how you would do the maths. and we will see if that matches up with what other people have done online. Okay. Well, what I was attempting to do in my head very quickly. Yes, I know.

That's why I stopped you. No, I was just thinking like a plane takes off every couple of minutes at Heathrow. That's one of the busiest airports in the world. So I know that that's like a high watermark. There's a couple hundred people per aircraft. You're launching, you know, tens, an hour. and the average flight is a couple hours. So I was trying to work out how many people are in the air

just out of Heathrow based on how many people are taking off and how long they stay in the air. And so I was like, if it's a couple hours long, so it's a couple hours times tens times hundreds. I was like, oh, maybe thousands, tens of thousands. But then you're like, where how many airports are that size across the globe? Yeah. Again, I was like, tens.

Maybe if you factor in all the small ones, you get to 100. So I was like, that's why I was ballparking. 100,000. But that's what you, if you actually did some research, you would pull up like the average flight length and you could get the number of planes that take off in the world and the average occupancy of the planes. Or you could maybe skip taking off. I bet there are stats on, and I think Greg alluded to this in the question, there's probably stats on average uptime of aircraft. You can probably get number of aircraft in the world. I know we did that before. four for how many planes fit in a cylinder.

And you could get probably average occupancy rates. Yeah, I feel like you would, yeah, average occupancy times, like a percentage times number of aircraft size and number of them times the percentage of the time they're in the air. Yeah. That'll work. What's the internet say? The internet has done.

Or are there actually just stats on number of airline passengers per year? Precisely. And there's stats on average flight length. Yeah, okay. So there's flight radar 24.com. Now, the math that people have done is from roughly around the same time that book came out. So we might want to do some updated maths using these links. But some time ago, one person saw that on that website, it was showing that they're around about 9,700 planes in the sky.

I've read earlier this site would only feature ADSB transponder data, but apparently it has FAA data nowadays as well, considering its only commercial planes that's disregard all the old slash smaller ones, which are probably going to account for less than a percent anyway. There's also Rita dot dot dot.gov. The word dot is between two of those dots. Oh, the word dot is between the dots. Yes.

That's hilarious. So rita.org. Imagine working there and having to hand out your email address. There's a press release from 2016. that says that there are on average about 83 passengers per plane. We're really averaging out. So they've done, you know, 83 times 9,700 at this current moment. So they're looking about...

Was it 83 an aircraft? Yes. I imagine it's more, but I guess they take into account that some flights aren't full. Lots of small planes and are full, yeah. So they came in at about 800,000 just over of people in their sky. someone else is linked to a link that is actually down but it was originally going back to the International Air Transport Association they give monthly revenue passenger kilometers oh great unit so in 2012 it was just over 450 billion they had the year on year growth at 20 year average of

5% they were looking at forecasting oh that okay that'll give you the inflation of this figure yeah but you need to know average flight length well They've also done given takeoff speeds and cruising speeds. Oh, okay, they're done by speed. Okay, fine, yeah. That gives you time. Then 500 billion revenue passenger kilometers per month, therefore translates to 685 million revenue passenger hours per month.

This is equivalent to an average of 940,000 people in the air at any given time. So that's how they paint to that answer. They also then redid the maths taking into account how many of those people are probably crew. Oh, plus crew. Yeah. Plus crew. So that took them up to 995,000. And then we had another person who just says,

American National Air Traffic Controls Association says about two times 10 to the power of six passengers per day. $200,000. Assume even flight distribution throughout the entire day and that each flight lasts for about four hours. So about 333,000 Americans in the air right now. According to the CIA World Fact Book, America has 13,513 of the world's 41,000. 788 airports. Slightly more than the tens. Oh yeah, but I was, you've got to lump them into

Heathrow-sized pots. I still reckon it's probably going to be a few more out of that. Agreed. I think that's, that might be where my calculation underestimated. And they've cited sources as well. They have come to the conclusion of about a million people flying right now. So all of this backs up your findings, Laura, from that book. And it all seems to be around that time.

Yeah. I mean, it's quite reassuring. to know that there are facts in that book. Yes. Yeah, you'd hope so. Yeah, can you imagine if you found out it was all lies? I'll never fly again. What else can you believe? Absolutely nothing.

Now, what I want to say, and you might be familiar with this, I'm sure some of our listeners are, I did enjoy the fact that this is from a subreddit called They Did the Math. Yes, I saw that link. There is another subreddit called They Did the Monster Math. That's correct. It's very enjoyable. So, knowing this and seeing how. people have decided to figure it out.

And this was 12 years ago. Matt, you have been silently checking little things, writing down notes. I have. I've been reading this out, which leads me to believe that you have been looking up your own potential answer for today's day and age. This is it. Yeah. I was like, I was wondering how fast I could just dig up current numbers and flight tracker. Yeah.

And I ended up using a website called Flight Aware. A very similar thing, tracks all the flights. Flight tracker currently tracking 13,872 aircraft. Wow. So it's up a bit. On the 9,000. Extra third, maybe, a bit more. Not quite extra half.

There's more aircraft in the air now. Occupancy seems to be, you said 83 passengers. I'm seeing a few places give around 83% occupancy. But that might be about the same. I was just then trying to work out what the average aircraft size is. They seem to say between 150 and 300, give or take, I don't know. It feels a bit high personally. But if we took the average, naively took the average of that of 225 capacity.

So we times that by 0.83. And you're going to work out by occupancy as well. Yeah. Cool. So capacity times occupancy times number of aircraft in the air right now. It's 2.5 million. if you just took the 83 people per aircraft is still true that's like 1.1 million. I would say pretty confidently, it's somewhere in the millions.

Yeah. Over a million right now. Maybe two, maybe two and a half. Probably realistically an Adelaide size. An Adelaide's worth of people in the air right now. That's how I always measure a million. I know that Adelaide's just over a million. Yeah.

So whenever I hear that, I'm like, oh, an Adelaide. So yeah, like a whole city's worth of people. It's a lot of people. Which is impressive. Put them down. Yeah. There's a lot of people. Yeah.

I mean, there is also just a lot of people. Mm. Like, that's a tiny percentage of the U.S. population. Well, the question was, actually, how much of the world's population? Oh. Is in the air at the moment. Well, if we take 1.1 million as are lower bound, and there's currently 8.3 billion, so 8,300 million, that's as a percentage, 0.013%.

So somewhere between 0.01% of the population and 0.03% of the population. That's a lot. Yeah, that's bigger than I expected. That's definitely more than I expected. That's nuts. That means there are more people in the air right now. Right now. Than they are living in.

Listening to this podcast. But only does. Joe. We're coming for them. That's what our new goal should be. An episode of this podcast takes off every two weeks. Twockley. On board.

There are more people in the air right now than there are living in San Francisco. Dang. Or living in Geneva. Okay. Or living in Edinburgh. Are you reading off a list of cities above population? With less than a million? Yes.

Oh. Yeah. So, yeah. Wow. There's a lot of people. I feel like saying about a million, one to two million, I'm very confident in that number. So it's a lot more than the 300,000 that you initially thought. Correct.

But I was off by an order of management. I did also make it very clear that you had to say a number now. Yeah. But I'm also, I am surprised it's that bit. It's a lot. I'm convinced it's right, but I'm like, that's too many. I wouldn't have thought. They didn't all need to be somewhere else.

Yeah. I was surprised when I saw the results. Stop it. And I'm glad when I got it. Stop burning jet fuel up there. Matt, of all the people in this room right now. Oh, yeah, all valid. Yeah, okay.

But my work's important. Everyone who flies more than me is reckless. Someone has to smuggle salt somewhere. Dang it. Now I can't do anything without. You're like, well, the salt was pointless. And you're right. Thank you for, do you know what?

Have you noticed how I managed to not answer that myself at all. That was all everyone else. But look at how well I did it. Well done. Yeah. I got you to answer my problem. I know.

That's it. I'm going to outsource mine to you. I realize the key is for me to choose a math problem and then go, oh, I don't know how to do it. Well, they want to let us know if you're happy with all of that, Greg. Oh, hang on. Right. Let me.

How many Gregs are in the world? So according to my namestats.com, they're roughly one in every thousand people in America are called Greg. Okay. Oh, there's millions of people in the air. And one thousandths of that would be thousands of people named Greg in the air. However, if they're all American. Culturally, yeah, exactly. So it's under that.

I would safely say at any point in time, there's under a thousand Gregs in the air. There you go. There you go. And you're one of them, Greg. Well, well done. Greg, let's know if that sold your business travel boredom. Our next problem comes from Etienne, who said, thought this is a question you might be interested in. It's for you, Matt. Yep.

When does pound, then they've put in brackets, LB. So the weight. Yeah. And then they've done double equals sign. Yep. So when does it really equal? That's what it means. That's what it means.

Pound and then the symbol for the currency unit, yeah, in brackets. Double equals, by the way. Yeah. programming thing. Single equals is like when you're assigning a value. Double equals means is it equal to and single equals means make it equal to. Got it. So this is saying double equals are saying if you were to, that wasn't like a programming,

like a bit of code that would return true if they were equal and false if they don't. Yeah. There you go. Because in normal language we use equals in both senses. And so in programming you got to specify which one you mean. We should say double equals. So back to the question. They've also added what notes slash coins can use to make the worth of the currency also its weight?

Ah, yeah. I mean, I think what they're alluding to here is back in the day, pound sterling. Would be a pound sterling. Yeah, silver. Yeah. Yeah. Yeah. Or I think it was like 240 silver pennies to the pound sterling.

Oh. Yeah. Wow, that's a very specific amount of pennies per pound. Yeah. And it was like that until, oh, when did the UK went decimal currency in the 70s, I'm pretty sure. Australia was in the 60, 66 Australia went. We were before? Yeah.

Ah, take that. Take that. Take that British overlords? Exactly. I think we were less attached to it. To be fair, they'd had 240 pennies to the pound since like the 700s. So they had a bit of momentum behind it. Whereas it was easier for us to change.

Yeah, we hadn't had that. Well, we didn't care that much. We're the new Pat riots. Exactly. We're innovating. Fact-checking lawyers over there. How am I doing? Yeah, you're back on.

Australian decimalisation was the 14th of February, 1966. Valentine's Day! How romantic. Instead of Valentine's Day, we should be celebrating... Waiting decimalization of currency in Australia Day. Yes. The UK, decimalisation occurred on the 15th of February, 1971. 71.

What is it with Feb? So, anyway, what? I think a person here's on about is back in the day, a pound of silver was worth a pound. Yes. Because that by definition, a pound was the value of a pound of silver. I was like, okay, well, what does this person want me to do here? There's two things. What note coins can you use to make the worth of the currency and what weighs a pound in is worth a pound.

So I thought I'd double check silver, just to see how far off we are, way off. It was on the order. I mean, prices fluctuate at the time of my research. 1,289 pounds currency per pound of silver. Whoa. We're way off. Yeah. The times have indeed been a change in.

So some are cheaper. Steel rebar. That's like 15 pence a kilo. Bargain. Oh, sorry, these are all pounds, not a kilo. Sorry, that's 15 cents. I'm sticking with it. I got so many columns in this bridge.

And I hate all these ridiculous units, but I had to convert. And all the metal prices, some of them are in pounds, some are in kilos, some are in ounces. I had to convert them all over to find out the one that's closest. In second place, zinc at a pound and 11 pence per pound. But just beating it, aluminium. Oh. One pound, seven pence, current spot price, aluminium per pound. or aluminum or aluminum if you're wrong exactly so there you are so if you're talking metals the closest

metal I could find to being a pound per pound is aluminum. So there you go. Now I don't think that I think that's just like you know chunks of it not like kitchen foil but you get the idea. Well yeah I can try. Yeah but speaking of groceries. Yes. You and I went to the grocery store. We did.

I was like, let's go find things that cost exactly a pound per pound. Yes, you took me to a supermarket without a shopping list. Oh, yeah, I regretted that after. When I hadn't taken my medication. I had to send producer Laura back in to get you. I was like, if I go in there, Beck's just going to have more questions about ratios. You took someone with ADHD to a supermarket without a shopping list. I know.

I'm sorry. I see the error in my ways now. I was in there so long that Laura ended up signing up to one of those charities at the front of the supermarket. Yeah, I'm still waiting on the other side of the road. Okay, so here's what we found via what ended up being quite an exhaustive search. Worth it. When we were in there and we were a team, we did the conversion in advance,

that's something that cost two pounds 20 per kilo. Yes. Because a kilo is 2.2 pounds is a kilo. So 2 pounds 20 per kilo would be a pound per pound. So we were just looking for things that are about 2 pounds 20 a kilo. Yeah. I like that you said that we figured that out. You figured it out after I kept going back to you and going, what am I looking for?

I then explained it to you a slightly different way every time. Yeah. I got there in the end. And what if you just buy less of it? Yeah, that was at one point I was like, what if it's 20? You found one that was exactly 10 times. Yeah, it's too expensive. And you're like, this is exactly 10 times more expensive than we won't need it to me.

But the digits. But I was like, but if you buy a tenth of it, and it's like that doesn't change the value. That's like saying, I'm going to buy a kilo of gold. And it'll be cheaper if I buy a hundred grams of gold. So what was bang on the money at exactly £2.20 per liter, two side-by-side products and took a photo of these, Sawyer milk and almond milk by the brand for these was Elpro. So both exactly the same price. Yeah.

Not including the packaging. And then I started thinking, wait a minute. Do you know it's not including the packaging? Yeah, because that's just like, it's a litre of milk. Cost £2.20 for that litre. But the litre isn't including the packaging. And actually milk's probably ever so slightly more dense than water, but probably not by much. Do you say it's not including the packaging?

No, no, include the packaging. So then I started getting obsessed about what can I buy that costs exactly a pound per pound just as a product, like the item. Yeah, because you're not going to be like, oh, here, I'll pay for that with five pounds worth of soy milk and then you just... You pour it into the hands. Yeah, exactly. Yeah. So I looked slightly to the side and came across Otley chocolate deluxe Oatly. Chocolate Deluxe Oaties. drink. It was still a liter, but two pounds 45. And I just pure guess thought maybe, it's a bit like my guess about how many people are in the air at any point in time. I thought maybe that's about the packaging. But I didn't think it through at all. But I have the milk here and I have some scales.

Yes. So I'm going to weigh it and I'm going to put it in this spreadsheet and it's going to tell me exactly how many currency pounds per pound of mass this is. Okay, I'm weighing it. 1,081.3 grams. That is 1 pound, 2.8 pence per pound. Ooh, that's pretty close. That's not bad. I'm semi happy with that.

You, however, Beck, invested more of your time in solving this problem. Well, because of my ADHD, hyperfocus. I'm just trying to turn it into a feature. Yes. Just as you sent in Laura to come and fetch me, my eyes befell upon a 500 gram bag of brown basmati rice. Yep. Which was £1.10.

1.1 pounds, putting it on the spreadsheet, yeah. Now, obviously, this is including packaging, but I would argue the packaging is probably pretty light. The packaging is a pretty small percentage of that mass, yeah. Do you want to weigh it for... I like the fact I bought like a sweet chocolate drink. Like a delicious... Yeah. Recreational, you know, confectionery-esque beverage.

And you bought a bag of plain dry rice. Yeah, it's like we swapped. Yeah, we bought each other's personality as a product. Maybe it's because I had a chocolate milkshake for lunch. Oh, right. It was subpar and now I feel stung. Well, we can drink some of this in a moment. I'll tell you if it's better.

Okay, here we go. Okay, I'm putting the rice. on the scales. 518.2 grams, typing that in. That's much more than I expected. Oh, you're so close. That's 96.3 pence per pound. But that's not as good as yours.

Not quite as close. Let me just, you're within 3.7 pence and I was within 2.8 pence. So I was slightly closer. Over and you were slightly under. So here's the thing. Yep. So that was £1.10 for a 500 gram bag.

But because it weighs more than 500 grams, it has... Yeah, it's too heavy. Which means you're getting too much rice for your price. It's getting cheaper. Yeah. And that's why you're slightly under your target. That said, we were wrong in similar amounts in different directions. Yes.

So if you were to mix these two things together... Well, producer Laura did suggest that we make some form of rice pudding. That we would be within a penny. That's pretty good. Of the pound, pound. Yeah. Which is not bad. I mean, the rice will be easier to carry around.

So I would say rice and alternative milks. Yeah. There you go. That's the question. For completeness, I looked up just the cost of elements. and you can get argon for a pound 49 per pound. That's the closest like pure element from a website that's just like here are the prices of the elements. I then looked up just any other material and PVC plastic.

Your generic hard plastic is a pound and nine pence per pound. and 98 pence per pound by mass soda glass. What's soda glass? Cookware. So some Pyrex branded things would be soda glass. That's almost exactly a pound per pound. That's not bad. They then did say what currencies weigh an amount of mass where if you had a pounds worth of currency, UK pounds.

Yeah. And you weighed all those coins. It's not going to be notes. They're way too efficient for mass. value. You weigh those coins. They weigh exactly a pound. And you can exchange them for a pound. And not many are very close at all. I checked a bunch of currencies I could think of because I had to download the masses of all the coins of each one. The closest Aussie one is not a million miles away. The one and two cents coins. One and two cents in Australia, the two cent weighed exactly as much

as the one cent, which is kind of fun. Huh. And they are a pound and eleven pence. of cost per pound of coins, would they still exist having been phased out decades ago? So we don't have them anymore. Yeah. Like the US coin, that got phased out quite recently. And that's way off. It would be about 75 pence per pound of pennies in the US. Canada, coming out of nowhere, 96.4 pence per pound of Canadian pennies.

Do Canada still have pennies? Do Canada still have pennies? Nope. Ah, they're gone. So? And then at the very end of all of this, it occurred to me that actually the pound that they used to use for a pound of silver is not a current definition of a pound. It was a tower pound. What's a tower pound?

It's a different number of grams. Oh, God. A tower pound is about 350 grams. What? Which would bring, I reran all the numbers, the US penny, which just ceased to exist. They're still kicking around, though. If you've got time to grab US pennies before they're gone, 97.2 pence per tower pound. That isn't to say you'll get a UK pound for them.

Yeah, you would. If you measured out a mass tower pound of US pennies, and you take them to a bank or someone exchange them into great British pounds, you'd get 97.2 pence, basically a pound. Yeah. So I'm glad to understand that. It's a stupid sentence for a ridiculous problem. Yeah. But the answer is, use the original tower pound. and grab US pennies before they go out of circulation.

Power pound sounds like a move you'd use in Street Fighter. I thought it was like a wrestler. Yeah, do the towel punch. Yeah. That was the most PG analogy I can. I was about to say, yes, well done. I appreciate. I thought that pause was your brain denying parole for a lot of jokes that we had to get out early.

So there's your answer, Etienne. US pennies. Or some slurries. made from chocolate oat drink and basmatti rice, packaging included. You decide. Yeah, I'm going to give that a pounding. Personally, I don't know.

Etienne, let us know. I want some milk now. And now it's time for any other backliners, different position in football. Now, I've been warned this is like almost 100% tooth day suggestions with maybe a treat at the end of some rock-related chat, but we'll get there. Beck, what do we got? Right, we got loads of suggestions from people as to when we should do our tooth special.

Yep. What date? So a lot of people suggested the 13th of February. Right. Because 2 for February and 13, 2.13 sounds like tooth hurting. Okay, yep, yep, it's got precedent for that style of pun. Seeing as we can't do 230. Yeah.

Due to February, dumb February. February. 213. 213. 213. Oh, yeah, fine. Yeah, fine, fine, for fun. Craig suggested the Tooth day of the tooth months.

Oh, that's not bad. So the second of February. Yep. James and Jason contacting us separately, both suggested August 18th because it's the 230th day of the year. Ah, there it is. That's all right. Benadict Comfer batch.

Yeah. I doubt that's their real name, but look, I'm not here to shame anyone. Said, I propose we celebrate Tuesday on the 30th Tuesday of the year, because Tuesday sounds like Tuesday with a lisp. Yeah, okay. And then they said, choose 30. Well, I would also argue. And why the 30th? Being a dick, I would also argue like choose, sounds like chew, as in chewing.

Chewing. Yeah. 30 would maintain the spirit of 230, 230 joke in a more pleasing way. Yep, yep, yep, yep, yep. This year, Tuesday the 30th would fall on July 28th. I like the concept of the nth day in the year that's difficult to calculate. Yes. That pleases me.

I also like it being a Tuesday because of chewing, yep. It does mean that the episode wouldn't come. out on that day because our show comes out on Mondays. But it'd be like, Tuesday Eve. Yeah. Yang suggests that Tuesday should be the second of February. Second of February. Two to February.

Two to two. It says the second day, the second month. It works either way around. There's no arguments. Bonus, Tuesday, 2007. This links back to the last one we said. Yeah. Would be on a Tuesday.

Right. Yang again has said tooth day But I will say Come on guys Tuesday C-H-E-W It's right there Alternatively

if you want to be exponential about it We could have it on 4-4 Being tooth-power day On tooth-power month And they've also suggested That we could have it On the first

Tuesday of the year Oh yeah Okay I do enjoy this Yep We heard from Aaron Who said A possible solution For your Toothay Conundrum

one, two, three or one tooth free. It doesn't even have to be in US date format. It could be the 23rd of January or the 12th of March. Unbelievable. I do like one, two, three. That should be International Counting Day, surely. One tooth free. One tooth free.

It's great. Is it? I like it. Frederick says international teeth day should be 12th of the 30th because that could also be read as 1-2-30. So it's a similar One two hurdy Yep

Quite a few people gave us sort of letter sum Ones like we did in that numerals Oh we did a whole thing about adding up the letters When they become numbers Yeah So quite a few folks have suggested Variations on the words

Teeth Day or Tooth or Tooth As an example Of one But this isn't to say There's so many back You're not going to read them all There are actually so many That I'm not going to read the ball

I'm choosing the one One at random Whose answer was the shortest LeVisa suggested April 18th is that is the 108th day of the year and the letter sum of tooth day is 108. There it is. Okay, great. Yeah. James said they had a dentist appointment right after listening to the podcast.

Right. So while they're in the chair, they asked their dentist. They were suggested the 28th of April being 28 teeth and four wisdom teeth. Okay. I can get behind that. Yeah. It's at least a different way to just. justify a date, then it sounds a bit like tooth.

Yes. I asked my dentist, too. Oh, yeah. What did your dentist say? They didn't know. They did say there's like a dental assistant day. Which I love. Yeah. But they said it in the kind of way of someone who keep being reminded that exists. When I did an evening of unnecessary detail recently.

Yes. And I did my talk about the tooth fairy. It was a lot of fun. In my research, I found out that, yes, there is a... International Tooth Fairy Day in February. There is also one on the 22nd of August, which is International Tooth Fairy Day. Why?

I don't know. I couldn't find... I couldn't find an explanation. I don't care. Let's do it. Yeah, but I was like, August, I can do that. Done. Okay. Can we just call it? Yeah, yeah.

I think what we're hoping for was something that would be like so obvious. Yeah, an unambiguous winner, but that doesn't seem to exist. What I do love is the entire. time we've been talking about dentists and teeth day. I've been drinking this sugary drink. Yeah. Okay. So we've got a bunch of suggestions there. At some point, we will announce what date we landed on. Yeah. And then I will answer all of your tooth-related questions. In time for our tooth special episode.

Oh, my goodness. Yep. That shall happen. Yeah. And we had some rock chat. Not as much as the teeth chat. Yes. People from Canada pointing out that there was a very popular children's book series about teacher Charlotte and her pet Rock Gertrude. So if you were to ask a Canadian what their favourite rock is,

apparently there's a decent chance they'd say Gertrude. Huh. That's interesting. Write that down. and Sammy came forward with a suggestion for Rock Day. They said 19th of January. And they said 19 is a good day for Rock Day because in binary, it's 10011, which is the binary ups and downs of the rock on symbol on your hand.

That's quite nice. Yeah. And what is the rock symbol, if not an upside down, tooth. There it is. 19th of June. Good suggestion, Sammy. I refuse to wait a year before we, there are too many questions. Also, I'm going to be in Adelaide soon where Dr. Sophie is and I want to quiz her on the questions in person. And an additional any other business, I will be at the Adelaide fringe in case any of our listeners happen to be in or around there at that time. I'm doing a work in progress at Rhino Room between the 10th and the 14th of March. So 10th to the 14th of March,

you can catch me at 745 at Rhino Room. Make sure you pre-book and I'd love to see you. I will be taking some Salt of the Perth stickers. So make sure you come up to me afterwards, say blah, blah, blah, and I will give you a sticker. There will be a link to the tickets in the show notes. Well, that's it. Thank you for listening to the podcast. We hugely appreciate you tuning in. I mean, these are fun to make. They're more rewarding if we know people listen to them. And a subset of those people, I mean, you're all valuable, etc. A subset of the fine listeners of this podcast also put their money where their podcast is

and they support us on patreon.com slash a problem squared. And to say thanks as a little token of our appreciation, we pick three names at random to mispronounce, which this episode shall include. Luck ass. Hi news. Ha. C.

Lintu Zill. There you are. If you'd like to have a non-zero, but still quite small probability you've been included in that list, you can go and support us on Patreon. So that's it. I've been Matt Parker.

You've also been hearing Beck Hill. And finally, producer Laura Grimshaw, who is a bit like the flying sky cam. That's because Bridges Lora is a computer-controlled cable suspended system. That flies around. Make sure the action is captured well and can be edited into a meaningful narrative. Oh.

Yeah. You didn't expect something remotely good at the end of that sentence. I know. It's almost like you're prepared. Thanks for listening, everyone. Bye. I go back and I'm afraid since our last record, some children asked,

they came into the studio while showing we've seen some of her friends around and they were like, hey, can we play Connect 4? Yeah, I walked in. You walked in and you said things we cannot repeat on this podcast. Because I assumed that an adult who had been in here had been missing about. Yes, it's unlikely children would be in the new year. What sort of person would do this in less nice language? And you pointed out, some children had asked.

Just looking at some young kids and I think it was like four, we've done four moves. I didn't know how to say, no, those are special moves that cannot possibly be recreated. So in the moment I said, sure, have a game. Have a game of connect four. We're not sure if we can recreate it based on how we've been recording it. Sit down, kids. Let me tell you about. Let me tell you about good notation methods for games of games.

connect four. Is that the current state? I think producer Laura's re-cated. Could you hold that up so I can see it? Oh, interesting. Okay. And whose go is it now? It's Bexgo.

Bexgo. Okay. But before I go, yep. We did hear from Reddit Game Guy here again. Who did not like how we were explaining the moon. I'm going to start feeling mean soon. And said, okay, so no ground floor.

No ground floor. I'm not sure how much of that was a joke. Nothing on this. podcast has ever been a joke. If Beck really is going to do days of the week, I have another question about regional variation. Is the first column Monday, Australia or Sunday? USA.

The answer is yes. Yes. It's one of them. Please don't do the column flipping thing for the person on the opposite side. You're not the boss of me. Look, Reddit Game Guy. I can't remember what side we're on. I've lost track.

If you do, please tell us who's looking at the book. board. No, none of us are looking at the board. It's compared with the previous moves. Okay. Okay. Okay. So now, Beck, you're holding the board right now.

Yes. And we're going to, from henceforth, this is the canonical way around the board's going to be. So that's it. That's your side. This is my side. Yeah. Okay.

Great. You'll go. I'm going to put my piece. Yeah. Next to your last one. Ooh. Was that clear? Beck has put hers in a position where it is contacting all of my previous moves.

That's unambiguous. I think every time, every third go, we can take one out. That uses a different notation. Laura, are you putting these photos onto Reddit and whatnot? No. No, I'm not helping. going on. You guys, use your imagination.

And we'll see how close to the real thing you are. Yeah. Yeah. That's the game.