A 4 by 4 "anti-magic square" is an arrangement of the numbers 1 to 16 in a square, so that the totals of each of the four rows and four columns and two main diagonals are ten consecutive numbers in some order.

The diagram shows an incomplete anti-magic square. 

4	5	7	14
6	13	3
11	12	9
10

Can you fill in the missing numbers (1, 2, 8, 15 and 16) to complete it?

Click to reveal an interactivity that you may wish to use to help you solve the problem.

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.