First, we played a cool multiplication game that I found on Pinterest. We rolled some dice, and colored in a matching rectangle: 2x4 gave us two rows of four. I made a rule that you had to color the correct rectangle, no breaking it up to fit better. At the beginning of the game, this was no big deal.
But as things went on, and our game board filled up, it became an important rule.
Not only did we each forfeit rolls that couldn't be placed on the board, but it also became very apparent that, although 2x6 and 3x4 both result in 12 squares, they are not exactly the same - the difference in those two rectangles could make the difference between scoring or not at the end of the game.
We played until we had 12 forfeits in a row; then we added to see who won.
Hero had never done extreme column addition before, and so this part was also challenging. I showed him how to break it up into manageable chunks, and how to carry when you need to carry a double-didget. It was fun! He wants to play again, and so do I.
Days where we play math are some of the best math days.