08202008, 09:02 PM


For primes and composites, I give the kids a hundreds grid and they have to get out two different colored pencils. We start with twos, color 2 one color (the color for primes), then color every other multiple of two the other color (color for composites), then we go on to 3, then on 4, we talk about the fact that it's composite so we skip it. Then move to 5, 7, 11, 13, etc, all the way to 100. Then they have a grid to look at. Soon, they get good at it. I always challenge them to be able to ramble off their primes faster than I can (I was forced to memorize them in school). As for trees, I don't really have any new ways to doing it, just the old fashioned way I was taught in school, but the kids do well with it.
