 Okay, let's do another video on exact and inexact numbers. This time we'll do a video on taking mass and determining exact and inexact numbers when you're doing something like this. So first thing we'll do is take our wayboat and put it on the balance. In fact if you want to you can look here, it says 2.03 which is actually an exact number. That 3 is an approximation and we'll talk more about that in a second. But anyways let's tear this, okay so it's at zero now. So take our copper shot and we're going to just throw a couple in there, a few I guess. So let's see if you guys can see. I'm counting 1, 2, 3, 4, 5, 6, 7, 8, okay so there's eight pieces or eight little copper shots in there and that's an exact number, there is exactly eight of them because I counted them 1, 2, 3, 4, 5. Now we're going to put them on the balance, we're going to see how much they weigh. So that's the mass of them, 1.25 grams, 1.25 grams which is an inexact number. In fact there are two certain digits, the 1 and the 2 and the last digit is always an approximation and this is what you find with all measuring devices, okay? So hopefully you've seen here that there are two types of numbers involved in weighing this particular type of substance, right? We can see that there's an exact number, there is exactly eight balls of copper shot that we're measuring, okay? And then when we put it on there we have an inexact measurement of 1.25 grams and anytime you're using a measuring device you're always going to have an inexact measurement, okay? Just like in the Beaker example that we saw last time, okay? Hopefully this answers those of your questions that had on inexact and exact numbers.