Have you ever walked by a really dirty car and run your finger through the grime to write your name? An artist named Ben Long does this to draw huge, beautiful, painting-like pictures on the backs of dirty trucks. By rubbing lightly vs. harder, he can make different shades from white to black and the greys in between. And since this is clearly dirt that rain couldn’t wash off, the pictures don’t wash off after he’s done, either. Imagine driving down the highway and seeing a giant picture of a dog or horse staring at you from the back of a truck. Ben makes his art with no paints, no brushes…he just needs a lot of soap and water when he’s done.
Wee ones: If Ben draws with his pointy finger, middle finger and thumb, how many fingers does he use? Count those fingers on your own hand!
Little kids: If Ben uses his pointy finger, middle finger and thumb, how many fingers on that hand does he not use? Bonus: If Saturday is the 1st “dirtying” day of no rain and Ben draws on the 5th day, on what day of the week does he draw?
Big kids: If the back of a truck is 8 feet wide and 9 feet tall, how many square feet of art can Ben make? (Reminder: Area is length (in this case height) times width.) Bonus: If the bottom of the back is 4 feet off the ground, and Ben’s hand can reach 7 feet 4 inches above the ground, how tall a ladder does he need to draw at the top?
Wee ones: 3 fingers.
Little kids: 2 fingers. Bonus: On Wednesday.
Big kids: 72 square feet. Bonus: 5 feet 8 inches, since the top is 13 feet high.
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.