Getting Your Arms Around It

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Getting Your Arms Around It

August 10, 2013

If you’ve ever hugged a tree and reached your arms all the way around, chances are it was not a sequoia. Aside from having one of every vowel in their name (a-e-i-o-u), sequoias are cool for another reason: they’re enormous. This photo shows the Grizzly Giant, a sequoia in Yosemite National Park in California: as you can see, a whole bunch of people can line up in front of its trunk! including long-ago President Roosevelt. Sequoias are the largest trees in the world by volume, i.e. how much air space their tall, thick trunks and giant branches take up.  Old Grizzly there takes up about 34,000 cubic feet, but the record-holder is the General Sherman tree in Sequoia National Park (also in California), who fills up over 52,000 cubic feet and whose trunk is 25 feet wide. At 275 feet it’s pretty tall, too, thanks to growing for over 2,500 years. Try getting your arms around that!

Wee ones: If a maple tree trunk is 2 feet wide and a sequoia is 20 feet wide, which one is wider?

Little kids: If one sequoia started growing in the year 150 A.D. and one was born in the year 250, which tree is older? (Reminder: we’re in the year 2013 right now.)  Bonus: If a tree is 9 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: If your armspan is the same as your height and you’re 5 feet tall, at least how many people your size would it take to hold hands and reach all the way around the tree?

 

 

 

Answers:
Wee ones: The sequoia!

Little kids: The tree born in the year 150.  Bonus: 5 feet wider.

Big kids: 75 feet around.  Bonus: 15 of you!

And a big thank-you to Jack R. for the great math topic and the photo!

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About the Author

Laura Overdeck

Laura Overdeck

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 while still in diapers, 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.

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