What You’re REALLY Wearing

Do you know what that picture shows? It’s a photo of blue jeans (on the left) and a shirt through a magnifying glass. Jeans are woven, so some threads run up and down while others run side to side to hold them together. The shirt is knitted, so the threads link together in a chain. If you can find a magnifying glass, look at your clothes in a whole new way!

Wee ones: If your jeans weave together white, blue and black threads, how many colors is that?

Little kids: If on your shirt 2 up-and-down stripes cross 2 left-right stripes, in how many places do stripes cross?  Bonus: What if you cross 3 stripes with 3?

Big kids: If the leg of your jeans is 100 threads wide and every other thread is blue, how many threads are blue?  Bonus: If there are actually 3 colors in a repeating order — blue, white and purple — what’s the greatest number of purple threads there could be?

The sky’s the limit: If there are 77 threads across, which one is exactly in the middle?

Wee ones: 3 colors.

Little kids: 4 crossings.  Bonus: 9 crossings.

Big kids: 50 blue threads.  Bonus: 34 threads, if the very first is purple, because then after 33 sets (bringing us to 99) the 100th will be purple also.

The sky’s the limit: The 39th thread. If you had just 76 threads, the 38th would be the end of the first half and the 39th would start the second half — they would straddle the center. Once you bump up to 77 threads, the 39th becomes the middle one, with 38 threads before it and 38 after it.

Recent Posts

Pick a Math Skill

Pick a Topic