than 16.
i'd say 28 is correct.
i looked at the upper left-hand side only.
in this part, there are 2^3 paths which produce math, because, at every letter we can either go up or right, and there are 3 places where we make the choice.
it's the same for the other 3, so it's 32 total, but, because we counted each straight path twice, we subtract 4 to get the number of possible ways to spell math to be 28.
i like it when my answer agrees with somebody else's. 