You can
put this solution on YOUR website! Use mental computation to identify the problem that has a product of 3,286. Explain.
51x64 (53x62) 42x93 38x77
You rule out 51x64 because the answer to that will end
in a 4, not a 6
You rule out 42x93 because that's even more that 40x90
which is 3600, which is way too big.
You rule out 38x77 because that's even less
than 40x80 which is 3200, which is too small.
So that leaves 53x62.
Edwin