When you’re in bed, you probably sleep on a nice bouncy mattress. It’s bouncy because it’s filled with foam and Slinky-like springs. It makes you want to jump up and down on it when your parents aren’t looking. Well, in the old days beds were nothing like that. A bed frame was a wooden rectangle with ropes stretched across both the length and width to hold you up. You then stuffed lots of feathers under the ropes to fill the frame — but only if you were rich and could buy feathers. If you couldn’t buy feathers, you stuffed the bed with hay, which was itchy and scratchy and full of bugs. Since the ropes stretched while you rolled around, every night you had to tighten them. And that’s why we say, “Good night, sleep tight, don’t let the bed bugs bite!”
Wee ones: When you look down at a bed, what shape is it?
Little kids: If you have 4 ropes stretched across your bed and 2 more running from head to foot, how many ropes do you have to tighten at night? Bonus: How many squares do the ropes make, including with the frame around them?
Big kids: If there are 10 pegs down each long side and 6 across — with the long sides and short sides sharing the peg at the corner — how many pegs are there? Bonus: If you have 7 ropes running across and 3 ropes down, how many spaces have ropes on all 4 sides?
Wee ones: A rectangle.
Little kids: 6 ropes. Bonus: 15 squares. Try drawing it! The 4 ropes divide the bed into 5 sections, and the 2 from head to foot carve those into 3 sections.
Big kids: 28 pegs. Bonus: Just 12 squares. There are 6 short rows with just 2 squares in each.
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.