How do we measure multiplication mastery? Is it about memorizing a small grid of times tables answers? If so, would a grid of up to 10x10 really constitute mastery, or would that accolade only apply for those who manage to memorize the answers from a 12x12 times tables? Or perhaps it should be held back for those succeeding up to 20x20 or 100x100?
No! I don't think multiplication mastery is about memorization at all. That would be memorization mastery, but not multiplication mastery. It would be useful for parlour tricks like memorizing shuffled packs of playing cards. But mutiplication is a skill in itself. After all, we didn't master addition by memorizing the answers to a bunch of addition problems did we? If we had, we would likely be able to handle addition problems like 7+8 yet be totally incapable of solving problems like 72+15 in our heads, and would be totally dependent on a pocket calculator for such heady problems.
One of the problems with most method-based approaches to the times tables is that each method (e.g. the 'fingers' method for the nines) is that each individual method solves part of the overall table of multiplication problems, but that the rest of the table needs to be covered by other individual methods. A fully comprehensive approach, however, addresses the times tables entirely, without leaving any gaps.