This short video will have you on the edge of your seat. A mama black bear and her cub are climbing the steep side of a canyon, and it looks pretty dangerous. The mama scales the sheer rock fairly easily, but for the baby it’s not quite so easy…watch how he does it. Black bears live across North America and come in all sizes; the daddy bears weigh between 200 and 500 pounds, but some have been found at 800 or even 1000 pounds. They’re strong swimmers and live mostly on fish. Mexican black bears like these are endangered — and if they’re taking on rock-climbing like this, we can see why!
Wee ones: If the baby bear’s baby brother also joined them rock-climbing, how many bears went rock-climbing?
Little kids: At birth, bear cubs weigh only about 1 pound! If 2 months later a cub weighs 9 pounds more, how much does it weigh? Bonus: If it then doubles in weight over the next 2 months, now how much does it weigh?
Big kids: If the mama bear took 20 seconds to climb the rock wall and the baby took 3 times as long, how much time did they take altogether? Bonus: As we see, bears are strong — even a cub can flip over a 250-pound rock! If the cub weighs 1/5 of that rock, how much does it weigh?
The sky’s the limit: If in 1 minute the mama can climb 3/4 of the canyon wall, the bear cub can climb 5/8 of it, and you can climb 1/7 more of the wall than the cub, who climbs the highest?
Wee ones: 3 bears.
Little kids: 10 pounds. Bonus: 20 pounds.
Big kids: 80 seconds. Bonus: 50 pounds.
The sky’s the limit: You climb the highest! You climb 5/8 plus another 1/7, or 35/56 + 8/56, which is 43/56 of the wall. Meanwhile, the mama climbs 3/4, which is the same as 42/56.
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.