Do you know what that top picture shows? It’s a photo of blue jeans 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 bottom photo shows a T-shirt that’s 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?
Answers:
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.
