 So this video really shows you how to measure very very small distances, perhaps the width of the ice lolly that we have down here. Now the first thing I'd like to use is a digital caliper. Now when you turn these on, the first thing to do is make sure that it is zeroed. If you don't do that at the beginning, then every time you have a reading there's going to be some error introduced. So I first want to zeroed it, then I'm going to open it slightly and I'm going to use this to measure the diameter of the ice lolly that we have in here. So if I just place it very very gently, the reading we get is 3.52 for that part of the ice lolly. Now the other thing about this, although we can maybe measure the width of things using the slider here, there's also a part on the back. Now this is designed for measuring the internal diameter of something. So perhaps how wide it is on the inside of the foot. And also at the other end, there's a thing that we can use to measure the depth. So this comes out, this can then tell us maybe how far those legs go in on the inside. So this is our digital caliper and it's pretty straightforward to use. What's a lot more tricky though is this thing here. Now this thing here is a micrometer, or a factory a micrometer. So this means we can measure very very small distances. Now this one here is a bit more tricky to use and a bit more tricky to read. So let's imagine that once again we're going to measure the diameter of this ice lolly. What we need to do is we need to put it within this part here. I'm just going to open the jaws up slightly. And rather than just tightening it in using the kind of the big knurl grip over here, if you tighten that too much, what it's going to do is going to form the thing that you're measuring. So the way to actually take your reading is to use the dial at the end. As you put it in, you'll find that there's a certain point where you feel a bit of resistance. So if you're tightened anymore, there's a small click. What we can then do is we can take the reading off this. So if we just zoom in on this, so this is a reading that we see on the micrometer. And a point to note is that these numbers around this part go up to 40, 45 and then back to zero. What that means is that one rotation of this part moves this part in and out by half a millimeter. And that's really important to note. So if I just set that back again. Now the numbers down here, effectively we have these go up in half millimeter divisions. So at the moment, if we count it along, we've got one, two, three and a bit millimeters. And the bit is equal to 0.20 of a millimeter. Effectively where this line lines up with a number over here. If we were to maybe take it out by one full rotation, then that means this is moved out by another half millimeter. And now this is reading three, then you have the half division and then point to zero. So this would be equal to 3.70 millimeters. Hopefully that kind of makes sense. This is just something that you've got to find at school, have a play around with and see how you get on. But if you want to go, what I'll do, I'll set it up to a couple of different values. You can have the go up, trying to read it. And I'll put the answers towards the end of the video. So here we go. This is reading number one. This is reading number two. Okay, this one here gets a bit more tricky. This is reading number three. This one is reading number four. And finally this is reading number five. So hopefully that made sense. This is a caliper. This is my chrometer. And you'll have something similar somewhere in your lab at school. And it is worth having a go with these practicing, measuring these small distances. And if you do that now, then it means that in the future, maybe when you need to maybe measure the diameter of a piece of wire. Whatever it might be in one of your practicals, you'll have a bit more understanding about how to read this scale that we have down here.