The way we multiply is something we take for granted, but at least we know why the method works: why, that is, we start from the right and why we carry over digits from one column to the next one on ...

This summer, battle lines were drawn over a simple math problem: 8 ÷ 2(2 + 2) = ? If you divide 8 by 2 first, you get 16, but if you multiply 2 by (2 + 2) first, you get 1. So, which answer is right?