The table below is called a magic square because, if you add together the numbers in any column, row or diagonal you get the same number.

In this case, the number you get is $15$, and so we say that the magic number for this magic square is $15$.

The table below is a magic square of integers, but with some numbers missing. Can you find the magic number, and hence complete the magic square?

If you look at the only complete diagonal, you find that the magic number for this magic square is $6$. Can you find integers from $\mathbb{Z}$ to finish the magic square so that the sum of each row, column and diagonal is $6$?

The magic number is $6$. Look at the column with $?,2,4$. We would need $?+2+4=6$, so what could be the missing number? [Note: $0\in \mathbb{Z}$ so this is allowed!]