Texting Marakech

Here is a game you can play by text...and your opponent will never know how you manage to play so well. First the game, then its secret.

How to Play

The aim is to have texted 3 numbers that add up to 15. Each player takes it in turn to text the other a number from 1 to 9. Text a number already texted and you immediately lose.

Here's an example game:

You text: 8
Your opponent texts: 5
You text: 2
Your opponent texts: 4
You text: 6
Your opponent texts: 7
You text: 1
and win with 8, 6 and 1 = 15

Notice that if you hadn't texted 6, the opponent could have done and won with 5,4 and 6 = 15.

The Secret

The Marrakech Texting game seems to need you to be amazingly clever at mental maths. In fact all you need is to know a simple bit of mathemagic: a magic square. A magic square is just a square of numbers where each row, column and diagonal add up to the same number.

You can use an ancient magic square to help you play the Marrakech Texting Game. Try and work out how yourself and then read on.