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Can you fill this 3 by 3 grid with the numbers 1 to 9, so that the number in the middle of each line (horizontal, vertical and diagonal) is the mean of the two numbers on either side of it?
Mean Square
Age 11 to 14
ShortChallenge Level 
Can you fill this 3 by 3 grid with the numbers 1 to 9, so that the number in the middle of each line (horizontal, vertical and diagonal) is the mean of the two numbers on either side of it?
You can find more short problems, arranged by curriculum topic, in our short problems collection.
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