IRA FLATOW, host:
You're listening to SCIENCE FRIDAY from NPR News. Happy New Year. I'm Ira Flatow.
For the rest of the hour, if you're fan of the TV show "Numbers," where they use math to solve mysteries, but you're, you know, you're not as smart as those math guys on that show - they are really smart - well, we've got a few easier problems for you.
And joining me now are two authors. You first met them last year with their book of "One Minute Science Mysteries," and now they're back with "One Minute Mysteries: 65 Short Mysteries You Solve With Math." Eric Yoder is a reporter at the Washington Post. He's also a freelance writer. Natalie Yoder, a high school student in Virginia. She happens to be Eric's daughter. And if you want to solve a math mystery, maybe try to play Sherlock Holmes yourself with us on the air, give us a call. Our number: 1-800-989-8255. 1-800-989-TALK.
And welcome back to the program, Eric and Natalie.
Mr. ERIC YODER (Author, "One Minute Mysteries: 65 Short Mysteries You Solve With Math"): Thank you for having us.
FLATOW: And why write a book, a follow-up book like this?
Mr. YODER: Well, we felt that a math book was a natural follow-up to a science book, since there are so closely related topics. And we really had that in mind, really, all along.
FLATOW: Mm-hmm.
Mr. YODER: Even as, well, as we were writing the science book, we thought that this would make for an actual sequel. And so we started working on this, really, as pretty much as soon as we finished the science manuscript. And now the book is out the printer and just about ready to go.
FLATOW: And Natalie, a lot of these problems are stuff you can really do in real life, aren't they?
Ms. NATALIE YODER (Author, "One Minute Mysteries: 65 Short Mysteries You Solve With Math"): Yes. You can really relate to math, and it shows how you can use math in daily life. And so that's one of the parts of the book, that - it just shows you how you can use math to solve daily problems.
FLATOW: Mm-hmm. Well, let's see if we can talk about one of the math problems in your book, or some of them. Do you have to know a lot of difficult math? How much math do you need to know to solve the problems there?
Mr. YODER: Well, not really a lot, because we aim the book at the middle elementary through about middle school audience. And so some of the problems are more challenging, but we also included quiet a few that really involve almost no math at all, but really, mainly knowing concepts and knowing how to apply a concept.
FLATOW: Mm-hmm. 1-800-989-8255 is our number. Let's - how about you say we go to one of the math problems?
Mr. YODER: Okay.
FLATOW: I'm gonna pick out a problem, and I will read the problem and we'll -maybe we can get a partner, a partner on line who I can play along with - Jeff in Columbus. Hi, Jeff.
JEFF (Caller): Hey. How you doing this afternoon?
FLATOW: Hey, there. You ready to - ready for this problem?
JEFF: I'm ready for this problem. Let's see what happens.
FLATOW: All right. I feel like I'm doing the puzzler here. But here - here is the problem. It's called sweet solution. And it goes like this: Come on, class, to the candy aisle, Ms. Hanson, called out. The class groaned at the thought of being in the candy aisle, knowing that they couldn't have anything for themselves.
They were on a field trip to a grocery store to buy supplies for a project. They had collected pine cones. They're going to cover them with peanut butter, roll them in birdseeds, stick on candy, tie the strings on the pine cones to hang in the trees outside the school. Patti(ph) was in charge of the candy. So tell me again, what do I have to do, Ms. Hanson? she asked.
Well, Patti, remember how we collected 200 pine cones? We're going to put five peppermints on each pine cone for the squirrels. So start counting while I take the other students to get the peanut butter and the bird seed. That's a thousand pieces of candy, Patti's friend, Lulu, said as they reached the candy. The peppermints each wrapped in plastic were in a bin were sold by weight. There was a scoop to use with a scale. Too bad they don't sell it in bags marked with how many are inside, Lulu said. It will take forever to count them. Actually, it'll be a lot easier than I thought, Patti said. What do you mean? Lulu asked.
Have you got an answer to how to make it easier? What do you think, Jeff?
JEFF: Well, if you could figure out on how many are in a pound, you can multiply that or divide that back out into a thousand and figure how many pounds you need.
FLATOW: That's pretty close to the solution, wouldn't you say, Natalie?
Ms. YODER: Basically, we said that if you know the weight of any 50 candies, then you can just multiply, and it would make it a lot easier.
FLATOW: So that's something like - that's something like Jeff said.
Ms. YODER: Mm-hmm.
FLATOW: All right, Jeff. I think you won that one.
(Soundbite of laughter)
JEFF: Fantastic. I appreciate it.
FLATOW: I wish I had some prize for you, just�
(Soundbite of laughter)
JEFF: Anyway, it was just fun playing. I appreciate it.
FLATOW: That's what we're doing it for. Thanks. Have a happy holiday. Happy New Year.
JEFF: Have a Happy Holiday, and a safe holiday, everybody.
FLATOW: You, too. 1-800-989-8255 is our number.
We're talking about, I guess, mathematics. How did you come up with the questions, Eric? Did you make these up yourself?
Mr. YODER: Well, we would often just come up with an idea where we would say, you know, we really ought to have our story where the problem revolves around this, and then we would kind of kick it around and twist it around and rewrite it until we found something that worked. And that's actually a common theme of a lot of these stories was it took a lot of writing to come up with something that was more than just a simple numbers problem like you get maybe on a math quiz in school. But to get something that really has a story behind it and to show how you can use math in an everyday-type setting.
FLATOW: Mm-hmm. Do you have a favorite one, Natalie?
Ms. YODER: Well, I remember one of the first ones that we wrote, my dad and I. It was the "Ice Cream, Anyone?" remember, if you have that on hand.
FLATOW: Do you want to read that for us, you want me to read it?
Ms. YODER: You can read it.
(Soundbite of laughter)
FLATOW: Okay. I'll do the reading for you. Here it is.
Ms. YODER: Okay.
FLATOW: Let's see if we can get somebody to play with us on the phone. Let's go to Rachel(ph) in Darien, Connecticut. Hi, Rachel.
RACHEL (Caller): Hi.
FLATOW: Hi, there. Are you ready?
RACHEL: I'm ready.
FLATOW: Well, okay. Here is the "Ice Cream, Anyone?" question. Welcome to Cora's(ph) ice cream parlor, a lady said from behind the counter. She was glad to fill up the seats in her ice cream shop on chilly day, but she hadn't counted on all these energetic middle school girls celebrating the end of their fall field hockey season. So you phoned earlier to reserve 21 seats for your team, right? She said to the coach, Mr. Lee. And he says, well, we're all set up for you.
And she pointed to the table that had been set with spoons and empty bowls. He had told the girls he would treat them to two scoops of ice cream each. Coach Lee, said Claire(ph), one of the players, you're always saying that each one of us is unique, aren't you? Yes, he said slowly, not sure he wanted to know what was coming next. So every one of us wants something different from anyone else, she said. And all the girls started laughing.
Boy, they're a picky bunch, aren't they? Cora said. I don't even have 21 different flavors, I only have 12. What can I do? Rachel.
RACHEL: Well, as long as everybody has two different scoops, you can do it. It'll work because like - even with 12, you can have as many different arrangements. You can have 21 different arrangements.
FLATOW: You mean different flavors, 21 different scoops?
RACHEL: Well, if they're having two scoops each, then they'll all have something different if they all have two scoops of something different.
FLATOW: Mm-hmm. Give me the bell. Now, I'm going to have to give you a good answer on that, wouldn't you agree, Natalie?
Ms. YODER: I would agree, yes. Just the number of combinations that are possible.
FLATOW: Wow. And these - and how long did it take you to figure that out?
Ms. YODER: I think I learned this concept in school and then I think I came home and said, hey, this would be cool. We should turn it into a Minute Mystery.
FLATOW: And Rachel, would you agree that's how you thought about it, too? How old are you? What grade are you in?
RACHEL: I am 14 and I'm in ninth grade. I learned this stuff when I was in math team in eighth grade.
FLATOW: Oh, you're one of these mathletes?
(Soundbite of laughter)
RACHEL: Kind of, I guess.
FLATOW: So you learned the combinations and permutations and things like that, that you could make with just two scoops of ice cream?
RACHEL: Yeah.
FLATOW: All right. Well, all I can wish you is a happy New Year. I wish - like I said, I have no t-shirts to give you or anything like that.
RACHEL: Happy New Year to you, too.
FLATOW: All right. Take care. 1-800-989-8255 is our number. Were there any you had to eliminate, that you said, oh, this is just going to be too hard, Eric or Natalie? Mr. YODER: Well, there was one involving area of a circle which, as I kept writing it, kept getting more and more involved. And I finally had decided that, no, we can't do it this way. And so I ended up rewriting it into a much simpler story. Although, the principle we were trying to get across, I think we managed to still convey that principle, which has to do with the relationship between the radius of a circle and the area. And there are actually several stories in the book that have area as a concept.
But the ones involving circles require a lot of explaining because, of course, there's a lot of math involved in calculating the area of a circle.
FLATOW: Do you go in with a concept that you'd like to explain and then make up the story?
Mr. YODER: Yes. Go ahead, Natalie.
Ms. YODER: We have a concept or we have something that we could turn into a concept. Like when I came home from school that we learned this, I said, is there any way we could change this into a story?
Mr. YONDER: Right.
Ms. YONDER: Or if we have - yeah, something like that.
FLATOW: Interesting. All right. Let's go to the phones for another contestant. Amy(ph) in St. Cloud, Minnesota.
AMY (Caller): Hello.
FLATOW: Hi, there. Are you feeling lucky?
AMY: I am.
FLATOW: Okay. Well, then you're in the wrong show - no.
(Soundbite of laughter)
FLATOW: I'm going to - you're ready for your quiz here?
AMY: Okay.
FLATOW: It's called Overdue Blues. And here it goes. Hey, Martha(ph). Have you seen that mystery book you took out from the school library? Her mother asked. We've got a letter from the librarian today, saying you've had it for 80 days, 80 days and haven't returned it. You're supposed to take it back after just two weeks. Whoops, I think I lost it somewhere, Martha said. How can I make it up to the school?
Well, the note says we can either return the book and pay the fine, or pay them enough to buy a replacement book, her mother said. Well, how much is each? Martha asked. It says the fine is 10 cents a day for every day a book is overdue. And it says the book you borrowed costs $7.50. The next day Martha went into the library, the librarian asked her, what are you going to do about the overdue book? What would you do, Amy?
AMY: Well, let's see. 80 days and the first 14 are kind of - it's 80 days overdue or is it, like, 80 days - I've had it for 80 days?
FLATOW: You've had it for 80 days. You're supposed to have it for two weeks.
AMY: So it's about 65 days overdue? At 10 cents a day, I would pay the fine.
FLATOW: Well, what do you say, Natalie?
Ms. YODER: I think that I would keep looking for it because if yesterday was the 80th day that you borrowed it, if today was the 81st day, like you could keep it - you had it for, like you said, 14 days without a fine. So I would keep looking for it because you would have another week to replace it. And you'd still spend less than the 7.50 cost to replace it.
FLATOW: You had the right the idea but you just got your little - you didn't have your calculator out, Amy.
AMY: Oh, I'm sorry about that.
(Soundbite of laughter)
FLATOW: Well, have a great holiday.
AMY: Thank you.
FLATOW: Thanks for playing. We're talking about math this hour. And we're talking about a new book that's going to be coming out "One Minute Mysteries: 65 Short Stories To Solve With Math" on SCIENCE FRIDAY from NPR News. When, Eric, will we see the book out?
Mr. YODER: Well, the book is at the printer right now and it should be available through the distribution stream within the next couple of weeks. It can be preordered from the publisher's Web site, which is sciencenaturally.com, or also from individual bookstores or from the big online booksellers are taking preorders.
FLATOW: Do you get schools buying up the book?
Mr. YODER: Yes. The first book, we had some bulk purchases buy some school systems, which was very nice. But most of the books are being bought by individuals, parents, and individual teachers, people buying them for their children.
FLATOW: And what age would we say would be ideal for this?
Mr. YODER: For this book, probably, roughly eight through maybe up to 13 or 14. One thing that we kind of discovered as we were doing this is that there really is a very wide range of math ability in those ages. And you might have some -much younger children who would be able to handle almost all the stories in the book very easily. You might have some that would challenge even an older kid. We did try to have a range of difficulty. And so, really, I think within that age range, just about anybody would be able to solve at least some of them.
FLATOW: Do you have trouble with all the different curricula around the country, that some teachers would say, this is not - it doesn't fit with mine, this does fit with mine?
Mr. YODER: Well, we haven't gotten that kind of feedback from - for example, from the science book, we didn't get much feedback saying, well, we don't teach that. I think what I discovered while we were working on those was I dusted off a lot of old math that was taught years back. And I'm not really sure that they teach all the same things today. Some shortcuts that are used in some of the stories, I don't think our kids have been exposed to the way that I was exposed to them when I was in school.
FLATOW: You mean like people just don't do that or use that arithmetic anymore?
Mr. YODER: Yeah, they don't use that form of arithmetic. I mean, for example, there's a story about rules of multiplication. And I don't know if they really teach those anymore, maybe they do. But from my experience, I haven't seen that kids have been taught the same principles, the shortcuts that we were taught when we were in school.
FLATOW: Yeah, well, with kids bringing calculators to class, where we would never be allowed to bring one to class.
Mr. YODER: That's - that's right.
(Soundbite of laughter)
FLATOW: But they're expected to and expected to use them, and they have graphing calculators and things like that. I guess you have to figure out where that sweet point is for kids in math these days.
Mr. YODER: Well, one of the things we tried to accomplish was that almost all of the math in the book can be done in your head, even for readers in the target age range. There are some stories where the explanation goes into a little more detail just to prove that it's true. But we really did try to make the math take a backseat to the idea of understanding how to apply the math. And you're right, if you've got a calculator in your hand, you may not need to understand some of the means of calculating that we used to be taught back in the old days.
FLATOW: Natalie, as you get older, are you going to bring the math along with you?
(Soundbite of laughter)
Ms. YODER: I think so.
FLATOW: I mean, as you get into algebra, calculus, will we be seeing these little �65 short stories to solve with calculus� or something like that?
(Soundbite of laughter)
Ms. YODER: I mean, maybe. It's always a possibility. But I think as you get - I don't think it would be a one minute mystery.
(Soundbite of laughter)
Ms. YODER: Well, I mean, it's - only takes a minute to read but it might be challenging to shorten something down that would involve like a calculus or...
FLATOW: Yeah.
Ms. YODER: ...like a trig function.
FLATOW: I understand that. I want to thank you both for taking time to be with us today and have a happy New Year.
Mr. YODER: Thank you and happy New Year.
Ms. YODER: Happy New Year.
FLATOW: You're welcome. Eric Yoder, a reporter at the Washington Post, a freelance writer. And Natalie Yoder, high school student in Virginia. Now out, soon to be at a bookstore near you, you can preorder it, it's called "One Minute Mysteries: 65 Short Mysteries You Solve With Math." And don't use a calculator.
Have a great holiday weekend. Happy New Year. Thanks for listening on this holiday, taking time to be with us today. Have a great holiday weekend. I'm Ira Flatow in New York.
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