Follow up: The game is really sinking in. This morning DS (correctly) told me about the laws of mathematics (Distributive, Communicative, Inverse Identity...) It's harder for him to pronounce the words than to explain the concept
He's also starting writing a series of "books", one for each mission. I'm glad that he's incorporating writing into his interest! (And I'm a little bit proud of him because at open house the teacher was talking about getting children to use proper capitalization for a single sentence, and he's correctly using quotations for character dialog, commas, etc.)
Good stuff!
JB