“Two, four, six, eight; bog in, don’t wait”. As children, we learn numbers can either be even or odd. And there are many ways to categorise numbers as even or odd. We may memorise the rule that ...

An even number is a number that can be shared equally into two groups. For example, these 4 cubes can be shared into two equal groups of 2 cubes. So 4 is an even number. An odd number cannot be shared ...