# Stuntin’

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.

# Stuntin’

September 16, 2014

We just love watching people do crazy stunts that use talents you didn’t even know people could have. This webpage has collected mini-video clips of folks flipping toys, tools and themselves through the air in the wackiest ways. We see one guy do a backward somersault and land perfectly on a floating chair in a swimming pool; another guy does a flying headstand over a table and lands his head right inside his hat; another throws the top of a Pringle potato chip container like a Frisbee, then eats a chip just in time to catch the top as it bounces off two walls. What we love most is that all of these tricks show people doing perfect math. How many feet away is that pool chair? How many seconds to eat that potato chip?  They have to get it just right to avoid going hungry or breaking their necks. Do the math right and maybe you can pull off these stunts, too.

Wee ones: Whose stunt takes longer, the guy sliding down the stairs for 5 seconds or the pool-chair jumper who flips for 2 seconds?

Little kids: If the potato chip guy’s top takes 2 seconds to hit the first wall, 2 more seconds to hit the next and 2 more seconds to come back to him, how long does he have to eat a chip?  Bonus: How many chips at most can he eat in 18 seconds if he does the stunt over and over?

Big kids: In the 14th clip, a guy on the ground throws a hot dog up to another person who catches it in a hot dog bun. If the roll holder catches every 4th throw starting with the 4th, does the hot dog land in the roll on the 52nd throw?  Bonus: How about the 126th throw?

The sky’s the limit: Around the 18th clip, a guy snowboards up a ramp just in time to fly up the side of a passing truck and flip over. If he has to slide 12 feet and the truck starts 28 feet away at the same time, and the truck is moving 4 feet per second faster than the snowboarder, how fast does each one travel to reach the ramp at the same time?

Wee ones: The stair-slider.

Little kids: 6 seconds.  Bonus: 3 chips.

Big kids: Yes — 52 is divisible by 4.  Bonus: No — 100 is divisible by 4 but 26 isn’t, so their total isn’t.

The sky’s the limit: 3 feet per second for the snowboarder, 7 feet per second for the truck. In time t the snowboarder and truck both finish their runs. So the snowboarder’s speed is 12/t, and the truck is 28/t. We also know the truck’s speed is 4 more than the snowboarder, so putting this all together:
12/t + 4 = 28/t

Multiply the whole thing by t:
12 + 4t = 28
4t = 16
t = 4

So the snowboarder slides 12 feet in 4 seconds, which is 3 feet per second. The truck drives 28 feet in 4 seconds, so the truck’s speed is 7 feet per second — and that is in fact 4 more than the snowboarder.

### 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.