BW wanted to do addition the other day. It was way too easy. He can add in his sleep. We’ve been trying to keep his interest in working with multiplication. So I told him I would teach him a multiplication that also had addition in it. Was he interested? BW jumped for it. This is how we’ve come to using the checkerboard (he had only minimal use last year and found it too hard to stay focused) to work on two digit multipliers. He is able to understand the concepts and is merrily working through multiplication practice to make ginormous answers. Everyone is happy.