Place the digits 1 through 9 in a 3×3 grid so that every row, column, and diagonal sums to the same number. What is that magic constant, and what does the completed square look like?
You arrange the numbers 1 through 16 in a 4×4 magic square (every row, column, and diagonal sums to the same value). What is that magic constant?
In this partly-filled 3×3 magic square (using 1–9), one cell is blank: 8 1 6 3 5 ? 4 9 2 What number goes in the blank, and what makes this a magic square?