I saw this sweet tangram tutorial at Elsie Marley last year and have had it nagging me ever since. She made hers from balsa wood, but I made mind from a 1X6. I just can't resist a chance to get out my chop saw. I love that smell.
I haven't given these to the kids yet, because I know the pieces will be lost and scribbled on. So for now, I'm going to learn how to make a bunch of shapes, then in a few years I'll wow them with my repertoire. If you haven't seen them before, it's a puzzle made of 7 blocks that you can rearrange in various ways to create an infinite number of animals, people, letters and things. You have to use all 7 and they can't overlap, but other than that its pretty open ended. No time limits or point systems, just free fidgety play. I love it! I've added a few sets to the shop.