We'll see, but some of the things you have been discussing were never "there" in the first place, so they won't be able to come back! (i suppose you'll be telling me there are octagonal numbers, too...) I'm sure DS4 will be telling me soon "i think [insert any name here] knows way more about math [or insert any other topic] than you do."
Oh, and I had to look up heuristics too.
I did, too, the first time I came across the word in teaching lingo, SPG. No worries there. Some of it is just experience with teaching materials.
I learned about triangular numbers from a "math with pattern blocks" book that I bought for this school year. I had never heard of them before that. Haven't we all made pyramids out of stuff before though? The concept is there, even if the terminology isn't.
I'm telling you, you're ahead of the game! Your child is three years younger than mine, and you know as much as I know on this subject already! So much comes out of the learning materials you find...
Oh, and from this forum, of course!
And now I'm off to look at that octagonal numbers link. I've never heard of those...