In this video we’ll first look at smaller and smaller objects in a series of steps. We’ll start with this Oak tree which is 10 metres tall. Can you see the boy underneath the tree? We’ll call him Lee, and Lee’s height is about 1/10th of the tree’s. That makes Lee 1 metre tall.

We’ll now zoom in using a magnifying power of 10, and that will make Lee’s image about the same height as the tree was on the screen before. In this video, we will continue to find smaller and smaller objects and zoom into them in a series of steps, until finally we can see an atom.

Now let’s find something about a tenth of Lee’s height- the distance between his eyebrows is about right. Let’s zoom in to magnify this by 10 so it’s bigger on the screen.

This distance must be a tenth of a metre wide. What’s a tenth of this distance? – the width of Lee’s iris- that’s the coloured part of his eye. His iris is a 1/100 of a metre wide. A hundredth of a meter is also called a centimetre.

We’re going to show you a trick here. 1/100 is the same as 1/10^{2} because 100 is 10^{2}. Scientists often write this as 10^{-2} . That’s like 10 squared, except that the 2 is has a minus in front. This minus is telling us that the squaring is on the bottom of the fraction instead of the top. The cool thing is that it’s quicker to write 10^{-2} than 1/100.