 Okay, for the real number set, I've set up some exercises. I want you to go on there and define which group a certain number belongs to. So the symbols that you're gonna be using is this. This represents element. Now what it means is, which number group does a certain number belong to? Is it the natural numbers, the whole numbers, the integers? So for example, I'm gonna give you a number. I'm gonna say which group does this belong to? What you're gonna do is say, well two is an element of the natural numbers. Which group would negative two belong to? Well negative two is an integer. So what you're gonna do is say two, negative two is an element of the integers. Now if you remember the real number set, we have the natural numbers, the whole numbers, the integers, and the rational numbers, right? Each one is a subset of the previous one. So what you're gonna have to do is take it down to the lowest value it can go. So two, now two belongs to the whole numbers set, the integers and the rational numbers. But what you're gonna do is take it down to the lowest set belongs to which is the natural numbers. So for example, if I give you the number zero, zero, the lowest it goes to is the whole number set. So you're gonna go zero is an element of the whole number set. And you also have the irrational numbers. The symbol for this is Q with a bar up top. Sometimes they use I and this one switches over. But I'll explain all that stuff on my website, okay? So if I give you an irrational number which is a square root of a prime number, any prime number, let's say square root of five. Now this number doesn't repeat and it doesn't end. It's two point blah, blah, blah, blah, continues on and the number, the pattern changes. So square root of five is an element of the irrational numbers set, okay? Now do the exercises, if you're getting them wrong, make sure you look at the video again and try to figure out how the real number set works. If you're still having problems, send me an email or post a comment on the website and I'll try to clarify any problems you have, okay? Good luck.