Have you ever held hands in a long line? How far did you all stretch? Our fan Lily J. asked, if everyone in the U.S. held hands, how long would that line be? We can use a very cool body math fact to figure this out: your arms stretch across about the same distance as your height! Measure your height and armspan to see for yourself! Let’s say for a mix of kids and adults, the average person can span 4 feet. So our 325 million Americans can stretch 1300 million feet, or 1.3 billion. Divide that by 5,280 feet per mile, and we could stretch 246,000 miles – just a little more than the distance from Earth to our Moon!
Wee ones: Check out your armspan! Lie on the floor and have a grown-up or friend place a book or shoe at your feet and the top of your head. Then turn sideways to stretch your arms across that distance. How closely does it match?
Little kids: If you’re 4 feet tall and your big cousin is 6 feet tall, how many feet taller is your cousin? Bonus: If you held hands side by side and stretched out, about how far across could the two of you reach together?
Big kids: If you and your friends are all 5 feet tall (and across), and you want to stretch a line across a 22-foot-wide ski slope, at least how many of you need to make the line? Bonus: In 1986, 6 1/2 million Americans made a line across the country in “Hands Across America.” At 4 feet each, how far could they have stretched in a perfect line?
Wee ones: Your height and armspan will match pretty closely!
Little kids: 2 feet taller. Bonus: 10 feet.
Big kids: 5 people. 4 people would stretch only 5 x 4 = 20 feet, so you need 1 more friend. Bonus: 26 million feet, which is just shy of 5,000 miles!
Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking before she could walk, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.