# Brainteasers

Age 7-11

Magic square

This is a magic square. The numbers in any row, column or diagonal have the same total.

But one of the numbers is incorrect.

Which number is it?

What should it be?

Age 11-14

Differences

Find the two smallest whole numbers where the difference of their squares is a cube, and the difference of their cubes is a square.

Brainteaser solutions from page 30

Magic square

23 10 17 4 11

6 18 5 12 24

19 1 13 25 7

2 14 21 8 20

15 22 9 16 3

Differences

The smallest whole numbers are 6 and 10:

102 - 62 = 100 - 36 = 64 = 43

103 - 63 = 1,000 - 216 = 784 = 282

Magic square

23 10 17 4 11

6 18 5 12 24

19 1 13 25 7

2 14 21 8 20

15 22 9 16 3

Differences

The smallest whole numbers are 6 and 10:

102 - 62 = 100 - 36 = 64 = 43

103 - 63 = 1,000 - 216 = 784 = 282

It only takes a moment and you'll get access to more news, plus courses, jobs and teaching resources tailored to you

## Latest stories

Helen Ward
18 June 2018

Will Hazell
18 June 2018
• ### Anger over Grenfell 'trauma' exclusion

Hélène Mulholland
18 June 2018
• ### 'It’s only one cheer from me on devolution so far'

David Hughes
18 June 2018

Natasha Devon
18 June 2018

Aidan Severs
18 June 2018

Emma Kell
18 June 2018