There may be no such thing as a unicorn, but a narwhal comes close. Narwhals are arctic whales that have a long, spiral tusk sticking out from the left side of their mouths. That tusk is actually a reeeeeeally long tooth that can grow over 10 feet long! People may have gotten the idea of unicorns from seeing narwhals pop up out of the water…unicorn horns in drawings from hundreds of years ago look a lot like twisty narwhal tusks. The Vikings thought the tusks even had magical powers. Narwhals can grow to up to 18 feet long, even before you count that tusk…It’s much easier for them to carry a 10-foot tooth than for us!
Wee ones: Who’s taller, you or that 10-foot tooth?
Little kids: How much taller than you is that 10-foot tusk? Find out your height to the closest foot! Bonus: A few narwhals have 2 tusks instead of 1. If there are 9 narwhals but 3 of them are double-tusked, how many tusks are there in total?
Big kids: In the summer, narwhals group up by the hundreds. If a group of 600 narwhals has 2 parents and 2 kids in every family, how many kid narwhals are there? Bonus: If your front tooth is just 1/4 inch long, how much longer is the narwhal’s 10-foot tooth? (Reminder if needed: A foot has 12 inches.)
Answers:
Wee ones: The tooth is taller.
Little kids: Different for everyone…subtract your height in feet from 10. Bonus: 12 tusks.
Big kids: 300 kid narwhals, since 1/2 of all the narwhals are kids. Bonus: 119 3/4 inches, or 9 feet 11 3/4 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.