My son who just skipped 3rd grade and is now in 4th memorized his multiplication tables in 2nd last year and then over the summer, promptly forgot them. He can figure them out pretty quickly and at his desk you would never know. Working one on one with him you notice that he is pausing and figuring it out. I figured he needed to work with them for a while. We have a week off at Thanksgiving and I will have him work on them an re-learn them. I found as a kid memorizing was difficult, it was just through repeated needing to multiply that they just became automatic. I can't imagine that every kid in the class has them all down pat and it doesn't keep him from doing his work and doing it well. It would just be to his advantage to put that behind him.
