Is there a best way to organize numbers so that it identifies the most traits within each number? (edit for clarification): a multiplication table gives simple detail to help understand multiples and divisors. Is there a more dynamic table that gives more detail to each number? For instance,...

I had trouble cracking this little puzzle from an elementary school 'math olympiad'. Find the missing number '?' in this array: $\begin{bmatrix} 4 & 1 & 2\\2 & 6 & 4\\3 & 2 & ?\end{bmatrix}$ Of course the real problem doesn't involve matrices. It's just a 3 by 3 grid with numbers. Somehow I an ...