 We'll continue our review of basic integer operations. And again, this is a review. It assumes that at some point you learned how to do arithmetic with side numbers, but you need some sort of refresher. And again, we have a set of rules for dealing with sign numbers followed by examples. This is the worst way to learn mathematics. You cannot learn mathematics by memorizing a set of rules and following some examples. If you haven't already learned the arithmetic of sign numbers, you won't be able to learn it by watching this video. Instead, I recommend that you watch these videos to learn the rules of sign numbers. So let's take a look at this and do a quick review. Given two integers A and B, I have the following rules. The negative of the negative of A is the same as A itself. The product of two sign numbers, if I have two negative numbers, the sign drops, the quotient. Likewise, if I have two negatives, the sign drops. If I only have one, that negative can attach to any of the factors. Likewise for the quotient, that negative can attach to any of the dividend or the divisor. That negative also can be pulled entirely outside the quotient or factor or product. And if I use the commutative and associative properties of multiplications, I can transform any statement involving sign numbers into a different statement involving sign numbers that I might be able to do. For example, negative five times three. So my first property, my property of the integer is negative A times B. Well, that's the same as negative A times B. So I can remove that negative to the outside, and this is going to be five times three. And now I have a set of parentheses. And the parentheses say do me first. So five times three is 15. Parentheses say do the stuff inside first. And there's nothing to do at this point. So I don't need those parentheses anymore. 15 divided by negative three. Again, I have a very similar property. Negative A divided by B is the same as A divided by negative B. So this negative can attach to either of the factors, and either the terms. And so I'll go ahead and move that to the numerator. This is negative 15 over 3. Another property says the negative of a quotient is the negative of the quotient. So I can move the group that 15 divided by 3. And again, parentheses say do this first. 15 divided by 3 is 5. And there's nothing more to do inside the parentheses. So I can leave the problem at this point. Five times a negative 8 divided by 2. Multiplication and division are co-precedent, which means I have to do them in the order that I see them. I multiply by negative 8 first, then I divide by 2. So I can begin by using the property. If I have a product that negative can attach to either factor, that negative that is attached to the 8. I can detach it and attach it to the 5. And again, my next property, the negative of a product, is the negative of the product. So that's five times 8 negative. Do the stuff inside the parentheses first. Negative 40. And again, if I have a quotient, negative something divided by something, that negative, I can separate out the whole number portion of the arithmetic. 40 over 2. Do that first. And I don't need the parentheses anymore.