# Pi Day of the Century!

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

# Pi Day of the Century!

March 14, 2015

It’s Pi Day, and today is the Pi Day of the century! Why? If you cut a string that’s the width of a circle, then wrap that string around the edge of that circle, you’ll need a little more than 3 of that string to reach all the way around. The exact number comes to 3.14159265… (it goes on and on for thousands of digits). March 14, when written as 3/14, looks like the start of that number, and this year matches even better because it’s 3/14/15! We use pi every day without even realizing it. If you wrap a measuring tape around your head, then take that length in inches and divide by pi, you’ll get the width of your head — and that’s also your hat size! Pi also tells you how many bike-tire widths the wheels have to roll to make one full turn. And when you bake a pie, the width of it tells you how much crust you’ll need around the edge…but you’ll have to decide how much of that you can actually eat.

Wee ones: What things in your house are circles? How many can you see?

Little kids: If you slice one pie into 6 slices and another same-size pie into 8 slices, which pie has bigger slices?  Bonus: How many slices do the 2 pies have in total?

Big kids: If your head is 22 inches around, about what hat size do you have?  Bonus: If your bike has 2-foot wide tires and you ride far enough for them to turn 10 times, how many feet did you drive? (You can round pi to 3 if you like, or use 3 1/7, or try 3.14!)