I remember thinking the same thing. But now I realize, I use it almost daily. You probobly do,too, and just don't realize it. The most obvious is in our quilting. Especially if you like to make your pattern up as you go, or if you change a pattern in some way. I have never been good at memorizing anything, therefore; I have had to know "why" something is what it is, so by making sense to me, I can figure it out. Moving furniture around, designing quilts, cooking (if you like to doubl, half, etc the recipe). I can't even think right now of all the ways I use it. But I think about it as I am figureing something out. "I sure am glad I took algebra and geometry in school". LOL Sounds like son is very gifted and just needs to know the why's of it all. Good luck and happy studying!! Oh, at least to my knowledge, the rules of both subjects have not changed, like the new math and some of the other subjects kids bring home for mom to help with!! New math makes NO sense at all to me. LOL