http://tomlinhollyblog.blogspot.com/2008/02/multiplication-puzzle.html
Hint 1: The A in the answer must be an even digit since Ex4 must be an even number. Therefore A must be 0, 2, 4, 6, or 8 (or Ex4 must end in 0, 2, 4, 6 or 9)
Hint 2: However A cannot be zero because the original number would then start with a zero. So A can only be 2, 4, 6 or 8
Hint 3: Since A cannot be zero, E cannot be zero because 0x4 would be 0 which would make A=0 and we can't have A=0 by Hint 1.
