DS does like math just can't be bothered to memorize these tables. When quizzed, would rather take 90 sec to come up with the answer rather than just "know" it cold
I think it's fabulous that your son enjoys "playing" with multiplication. I felt I went too quickly from being introduced to the concept to memorizing without enough opportunity to play around with multiplication.
You could help your son with shortcuts to figuring out the answer. For example to figure out 8x7 you could show him it's the same as (8x5) + (8x2). It seems easier to multiply by 5's and 2's and then add rather than adding 7 eight times.
