Rock, Paper…Bridge?

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.

Rock, Paper…Bridge?

June 3, 2015

Twisty arch stone bridgeA bridge just helps us cross from one side of something to another, and can be as simple as a wooden board across a stream. But bridges can get fancier than that. Arches are amazing because the pieces at the top have nothing right under them. They’re pushing sideways against the pieces on either side, and since they’re all wedge-shaped, no piece can fall out. Believe it or not, this red bridge is made entirely of paper! More than 4 tons of red paper were laid in 100-sheet stacks on top of a wooden frame; when artist Steven Messam pulled the frame out, the whole arch stayed in place. People can even walk across it. The second bridge shows a twisty arch of big flat stones, stacked by artist Dan Morales-Walsh. Many of those stones weigh over 30 pounds, but you can sit right under it without worrying it will land on your head.

Wee ones: If you build 1 bridge of stone, 1 bridge of paper, and 1 bridge of brick, how many bridges do you have?

Little kids: If that arch has 16 stones, what are the last 5 numbers you say to count them?  Bonus: If you weigh 40 pounds and the biggest stone actually weighs 10 more pounds than you, how heavy is it?

Big kids: The bridge of paper was stacked in clumps of 100 sheets. If the bridge uses 220 stacks of paper and your hungry dog comes along and eats a stack, how many stacks are left?  Bonus: If the paper bridge weighs 4 tons and your 10,000-pound bus drives over it, which one weighs more? (Hint if needed: A ton equals 2,000 pounds.)




Wee ones: 3 bridges.

Little kids: 12, 13, 14, 15, 16.  Bonus: 50 pounds.

Big kids: 219 stacks.  Bonus: The bus, since the bridge weighs 8,000 pounds.

And thank you Catherine M. for sharing that awesome stone bridge story!

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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 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.

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