This Week from Bedtime Math: The Socks Make the Outfit
A message from Laura: Bedtime Math is a pretty simple idea: we all know we should read to our kids at night, but what about math? My husband and I have done fun, mischief-loaded math problems with our kids at night for years, and when at age 2 our third child started hollering for his own math problem, we realized we were onto something: In a world where so many people say “Ewww, math!”, we had created a household culture where kids don’t just tolerate math, they actually seek it out. Now we email parents a fun, lively math problem every day to do with their kids – and every week, we’ll be posting a new problem right here on Scholastic Parents! Check out this week’s problem below.
No matter how many shirts you have, chances are you have exactly two tops you love more than all the rest. You probably wear those two shirts over and over until they’re so worn you can see through them. The same goes for your favorite pair of jeans. If that’s true, you’ve got a lot of company!
But, if you could just get excited about just one more of your shirts that you swear you can’t be caught dead wearing, and one more pair of pants, it’s amazing how many more outfits you could put together.
Wee ones: If you have 2 favorite shirts and 3 pairs of pants, how many outfits can you make, assuming all of them can match?
Little kids: If you have 2 shirts, 2 pairs of jeans, and 3 pairs of striped socks, how many different outfits can you put together? Bonus: What if you add in 3 more shirts?
Big kids: You have 4 shirts, 4 pairs of pants, and 4 pairs of stripey socks. How many outfits can you make? Bonus: What if one pair of socks has purple and orange stripes, and goes with only one of the shirts (and that shirt goes only with those socks)? How many outfits can you make now?
Wee ones: 6 outfits – Matching each shirt with one pair of pants makes 3 outfits. Then repeat for the other pants. So 3 x 2.
Little kids: Same reasoning as the first problem, but with more levels, so it’s 2 x 2 x 3, or 12 outfits. Bonus: You now have 3 shirts, so it’s 3 x 2 x 3, or 18 outfits.
Big kids: 64 outfits. Bonus: This is trickier. You have to carve out 1 shirt and the 1 pair of socks, which with each of the 4 pants makes 4 outfits. Then do the remaining 3 shirts and 3 sock pairs as usual – that’s 3 x 4 x 3, or 36 more outfits. So the total is 40 outfits.