Partitioning is a useful way of breaking big numbers up into smaller pieces, so they are easier to work with. Isn’t that right, guys? Take the number 23, let’s break it down. Not like that, like this… ...

You can’t always use a calculator or a pen and paper to work out a sum. Sometimes you have to work it out in your head. Sometimes it’s even faster. There is only one rule when it comes to mental maths ...