We always think of koalas hugging a tree, hanging on tightly — maybe to keep from sliding down. But scientists have found out the real reason our furry friends hug trees: to cool off. They saw that koalas always hug acacia trees, even though they eat eucalyptus tree leaves. It turns out that the acacia trunks are up to 9 degrees cooler than the air around them. Also, as the weather gets hotter, the koalas slid farther and farther down to thicker parts of the trunk, which are cooler. Koalas pant (breathe hard) to keep cool, the same way dogs do, but breathing fast dries you out. By hugging trees, the koalas save half the water they would have lost by panting. But we still like to think koalas hug just because they’re snuggly.
Wee ones: What’s the biggest thing you can get your arms around? Find it (or him or her) and give a big hug!
Little kids: If a koala hugs you with all 4 legs, and you hug back with your 2 arms, how many hugging limbs are there in total? Bonus: If a koala has nibbled on 8 eucalyptus trees, what numbers are the next 2 trees?
Big kids: If a koala climbs 28 feet up a tree, then slides halfway down for fun, how high off the ground is the koala now? Bonus: Scientists study a lot of animals to make sure there’s a pattern. If they studied 84 koalas and all but a quarter of them hugged trees, how many treehuggers were there?
Answers:
Wee ones: Items could include a giant pillow, stuffed animal, bean bag…or Mom or Dad!
Little kids: 6 limbs (arms/legs). Bonus: 9 and 10.
Big kids: 14 feet. Bonus: 63 koalas, because 21 of them didn’t hug.

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.