# Introduction

We can express a number as the sum of its place values.

For example, the place values present in “12345” are “10,000”, “2,000”, “300”, “40” and “5”. These can be summed to provide

Alternatively, we can break this up into

This is called expanded notation.

Sometimes it can be expressed as , but I’ve used brackets to make it easier to observe.

You can convert expanded notation back into simple form, such that

Although we’ve so far used (10,000), (1,000), (100), (10), (1), we can replace this with the information:

For example, instead of writing 12345 as we had above, it would now be