If you’ve ever hugged a tree all the way around, we bet it was not a sequoia. Aside from having every vowel in their name (a-e-i-o-u), sequoias are cool for another reason: they’re huge! This photo shows the Grizzly Giant, a sequoia in Yosemite National Park in California. Sequoias are the largest trees in the world by volume, i.e. how much air space their thick trunks and branches take up. The very largest tree is the General Sherman tree in Sequoia National Park. Its trunk is 25 feet wide, and at 275 feet it’s pretty tall, too. That’s because it’s been growing for over 2,500 years. Try getting your arms around that!
Wee ones: Find the biggest thing in your room that you can reach your arms around for a hug. Could your hand touch the other hand? The other wrist? Your elbow?
Little kids: If one sequoia is 8 feet wide and another sequoia is 17 feet wide, which one is wider? Bonus: If a tree is 20 feet wide and you’re 4 feet tall, how much wider than you is the tree if you lie down next to it?
Big kids: The distance around a tree is about 3 times the width. If General Sherman’s trunk is 25 feet wide, about how many feet around is the tree? Bonus: Using that answer, if your armspan is 5 feet, at least how many people your size have to hold hands to reach all the way around?
The sky’s the limit: If that 2,500-year-old tree grew 1 inch each year, would that be fast enough to be 275 feet tall now? (Reminder if needed: One foot has 12 inches.)
Wee ones: Different for everyone…it might be a giant pillow, stuffed animal, or a grown-up!
Little kids: The 2nd tree is wider. Bonus: 16 feet wider.
Big kids: About 75 feet around (it’s actually 25 times pi, or 3.14, which gives you 78.5 feet). Bonus: About 15 people.
The sky’s the limit: Not quite! Even if each foot had only 10 inches, you’d need 2,750 inches. And it’s actually more than that: 12 inches per foot gives us 3,300 inches. So the tree must have grown more than an inch per year on average.
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.