Imagine floating on the ocean and having a giant killer whale swim right under you! That’s what happened to Rich German in California. He was floating around on a paddleboard, and five orcas suddenly swam up to him. Orcas are the big, beautiful black-and-white cousins of the dolphin: males can be up to 30 feet long and weigh up to 6 tons. Even though they’re nicknamed “killer whales,” luckily Rich knew that they’re gentle animals, so he wasn’t scared.
Wee ones: 5 orcas swam up to Rich. What numbers would he say to count them up?
Little kids: If you’re 4 feet tall and the orca’s fin is 6 feet tall, how many feet above you does it reach? Bonus: If your bedroom is about 10 feet long, how many rooms that size would you have to line up to match a 30-foot orca?
Big kids: If you and your friends each weigh 50 pounds, and an orca can carry 200 pounds, how many of you can ride that orca at once? Bonus: An orca weighs about the same as a school bus. If your bus weighs 10,000 pounds and the orca weighs 1/5 more than that, how heavy is the orca?
Answers:
Wee ones: 1, 2, 3, 4, 5.
Little kids: 2 feet more. Bonus: 3 bedrooms — that’s how huge they are!
Big kids: 4 of you. Bonus: 12,000 pounds, since it weighs 2,000 pounds more.

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.