Have you heard that rhyme, “Hey diddle diddle, the cat and the fiddle, the cow jumped over the moon”? Why a cow? It’s a weird idea, since cows aren’t the best jumpers…all kinds of animals jump a lot better. Red kangaroos are the fastest jumpers, leaping 30 to 40 feet at a time at over 30 miles an hour. The hare, a cousin of the rabbit, can zoom at 35 miles per hour and can leap 10 feet — incredible for its size. Some tree frogs can jump 20 times their length. But wait: the annoying flea is only about 1/16th inch long, but it can jump 13 inches, over 100 times its body length! None of these animals can jump 240,000 miles to the moon, but they all have a better shot than the cow.
Wee ones: Who jumps farther, the hare that leaps 10 feet or the kangaroo that leaps 30 feet?
Little kids: If a kangaroo can jump 30 feet, how many 10-foot jumps does the little hare have to do to match? Bonus: If the kangaroo makes 2 leaps, how many jumps does the hare have to make to keep up?
Big kids: If you jumped 10 times YOUR height, how far would that be in inches? (Try rounding it off to feet, too, or measuring yourself!) Bonus: If a 1/8th inch flea jumps 13 inches, how many times its body length can it jump? (Hint if needed: How many times its length does it jump for each inch?)
Wee ones: The kangaroo jumps farther.
Little kids: 3 jumps. Bonus: 6 jumps.
Big kids: Different for everyone…take your own height in feet or inches, and multiply by 10. Bonus: 104 times its body length.
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.