Friday, March 14, 2014

Bedtime Math for Pi Day!

Bedtime Math 2; This Time It's Personal
by Laura Overdeck; illustrated by Jim Paillot
ages 3-8; 96 pages
Feiwel & Friends, 2014

Laura Overdeck has released her new book full of fun and crazy math - and just in time for Pi Day! Like her earlier book, this one is full of silly questions, puzzlers, and other math fun for kids who love to ponder stuff whilst in PJ's. And like her earlier book, there are problems for wee ones, for little kids, and for big kids.

But wait - that's not all! This time Overdeck includes a BONUS level where, she says, "readers can tackle math acrobatics that require two or more steps." And this time the theme is personal, with problems that feature spaghetti, underwear, duck-duck-moose, and the ever-annoying mystery of missing socks. You might notice that there are lots of socks all over the cover. What you won't notice, unless you take your book into a dark room, is that those socks glow in the dark.

I called Laura last week and asked her some questions about her book, math and Pi. First off, she pointed out that although her book was released this week (in honor of Pi Day) there's not even a slice of a Pi problem between the covers.

Laura: Pi is a really tough concept, and is a bit above the level of most readers (up to second grade) of this book. However, today's Bedtime Math blog will feature something Pi-related. The thing with Pi, and why it's important, is that people tend to underestimate the distance around circles. Or curves - if you're ever stuck in a traffic jam on a curve, you want to be in the inside lane. So knowing that Pi is a bit more than 3 helps people estimate the distance around a circle, or how far a ball will travel in one roll.

Archimedes:You've added a BONUS problem. Anything else new with this second book?

Laura: I expanded the type of problems for wee ones, making them more concrete. Now there are problems that ask them to count objects on the page, or determine what is bigger, or figure out what comes next. I wanted to make it easier for young children to jump into doing math. At the same time, I want to make parents comfortable with sharing math with their kids. Over the past couple years I've learned that people are reluctant to change things - so in this book I wanted to make sure that if we asked kids to count something, it would be an item almost everyone would have in their home.

Archimedes: What are the Crazy Eights?

Laura: We're launching a nation-wide math club that will be available to schools for free. There are four age levels: PreK, kindergarten, grades 1-2, and grades 3-5 - and they all feature hands-on activities. The idea is to make math a fun, social activity. Click here for more info.

Thanks, Laura - and now....  Time for Pi! One of the activities Laura suggested for Pi Day is to compare the distance around two circular things. For example: how much farther does a large bike tire go in one rotation compared to a kid's bike tire? Or how much farther does a beach ball go in one roll than a soccer ball? Or if you were a lego-man, how much farther would you have to walk if you were walking along the crusty edge of a large pizza compared to a medium pizza?

And what does this have to do with Pi, anyway?

Pi is the ratio of a circle's circumference (distance around) to it's diameter (distance across). Put in math language,  π = c/d. But don't take my word for it. Go on a Pi Hunt. All you need are a tape measure (or string), a ruler, a pencil and paper, a calculator and a few  round things: soup cans, the compost bucket, cheerios, m&m’s, a cocoa mug, cookies, marshmallows, cupcakes, a pizza….

Use the tape measure or string to measure the distance around your object (circumference). Now measure the diameter (the distance from one side to the other, through the middle of the circle). Divide C by d to get ... oh, perhaps you didn't get 3.14159. Not a problem – compare the circumference and diameter of another round thing. And another. Do any of them come close? If you get 3.14 you’re doing well.  Check out more Pi Day activities here and here

Drop by STEM Friday to see what other bloggers are writing for about science, technology, engineering and math today.

Review copy provided by the publisher.


  1. Thanks so much for featuring Laura and the Bedtime Math 2: This Time It's Personal book!

    For more Bedtime Math fun, join us on...

    Thanks again,
    Bedtime Math Community Manager

  2. This looks really great. Anyone who can make math fun for kids is a real hero. Thanks for telling me about this.