Have a look at this.  Magic squares are a brilliant way to give your brain a good work out. Every row, column and diagonal needs to add up to the same number.  Try them and let me know what you think.

If you enjoyed completing this activity or you feel as though you need a bit more practice click on this link.  If the link doesn't work type 'topmarks magic squares' into your internet search engine.  Be warned - it needs Flash in order to play so it might not work on your device.