We also have a lot of math chat at home, usually kid-driven. One of my favorites was teaching percentages while in the car on the freeway. DS6, then 4, wanted to know how fast I could go without getting a ticket. I told him 10% over the speed limit...I was on a freeway with a speed limit of 60 at the time, and on the way home we were on streets with speed limits of 40, 35 and 30. It was a fantastic exercise and he still "gets" percentages. We saw a sign in front of a Pawn Shop the other day and he commented that TV's were 25% off, so if we need one we should go get it there.
