Kangaroos think big. They can jump 9 feet high in the air and leap more than 20 feet in one jump, right over a whole car. So what can a mini kangaroo do? Check out Scotty, the baby tammar wallaby here. He’s so small that he can sit in your hand or inside a shoe! He weighs only 10 ounces (about 3-4 candy bars), and drinks milk from an eye dropper. Over a million wallabies like him live on Kangaroo Island off the coast of Australia. Let’s do the math to find out how far they can jump!
Wee ones: Baby kangaroos start small, too. Who weighs more, a 5-pound wallaby or a 4-pound baby kangaroo?
Little kids: If you can fit 2 cute wallabies in each of your hands, how many can you hold all together? Bonus: One pound has 16 ounces in it. How many more ounces does the 10-ounce Scotty need to gain to weigh 1 pound?
Big kids: If Scotty can jump 10 inches, an almost-grown-up kangaroo can jump 110 inches, and a baby kangaroo can jump the number halfway between, how far can the baby kangaroo jump? Bonus: How many feet is that, and how does that compare to your height? (Reminder: A foot has 12 inches).
The sky’s the limit: If a growing kangaroo can hop 11 times as far as a wallaby and that’s 90 inches farther than the wallaby, how far can each one jump?
Wee ones: The 5-pound wallaby.
Little kids: 4 wallabies. Bonus: 6 ounces.
Big kids: 60 inches (50 more than 10, 50 less than 110). Bonus: It’s 5 feet… see if you’re taller or shorter than that!
The sky’s the limit: The wallaby can hop 9 inches, and the kangaroo can jump 99. If the kangaroo can jump 11 times as far as the wallaby hop, that 9-inch hop is 1 part out of 11 equal parts of the jump, which means the 90 inches are the other 10 parts. So the gap of 90 inches is 10 times the wallaby’s hop, making it 9 inches.
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.