Adding and Subtracting Negative Numbers Simple Rules to Follow

In this video, I'd like to talk about adding positive and negative integers. And I'm going to work each of these two ways. One I'm going to kind of walk through flowchart, and then also we will complete them on number line, so you can kind of visually see what's taking place. lot of times it can get little confusing when you subtract when you're subtracting positive or negative number. And hopefully this will clear up some questions. Okay, up first, let's work through the flowchart. We have 8 plus negative 5. Is the problem addition? Yes. Are the you do you have same signs? No. So what we need to do is move down to here to no. It says subtract the smaller number from the larger number and keep the sign of the larger number. So will go minus 5 because 5 is the smaller number and that is 3. And then I'm going to keep the sign of the larger number, so it will be 3. So now let's see the same thing on the number line. So whenever you have negative number, the negative 5, you move to the left. So I'm going to start at positive 8. And remember am adding negative 5, so will move five places to the left. Negative you move left, positive you move to the right. So it will be 1 2 3 4 5. That becomes 3 and that is the You can't see that, but it's the same answer, 3. Okay, so the answer is 3. Let's work couple more. Up next, we have plus negative 9. Same rules apply. We have is the problem addition? Yes. Same signs? No. Subtract the smaller number from the larger number, keep the sign of the larger number. 9 - 5 is equal to 4. And 9 is larger than 5, so that will be negative. Okay, I'm going to move down to the number line, do the exact same thing. We start at 5. go nine places to the left. 1 2 3 4 5 6 7 8 9 gets me to -4. Okay. Let's try couple more. Now we have -6 + -4. Is it addition? Yes. Same signs? Yes. Add the numbers, keep the signs. 6 + 4 is 10. They were both negative. -10. Let's move down to the number line, see what's happening there. We start at -6. We have negative number, so we move to the left. 1 2 3 4 gets me at -10. Okay. Now, let's see what we have. Okay, now I'm glad we got to subtraction number. Is the problem addition? No, so I'm moved all the way down to here. Change the subtraction sign to addition, and change the sign of the number right after the subtraction sign to its opposite. So, we're going to rewrite this problem. Now we have -3 plus we change the sign, and now we have -6. Okay. So, from now on, ignore this. This is your new problem. In fact, I'm going to rewrite it. Plus -6. Okay. What did was changed the subtraction to positive, and then took the opposite of the opposite positive six that now became negative six, okay? So, now all do is work use the same sign the same rules as addition. So, here we go, okay? Okay, so we're starting over. Is the problem addition? Yes. Same signs? Yes. Then what we do is we add the numbers and keep the sign. So, we go 6 + 3 is 9 and they're both negative, okay? So, now let's do this problem on the number line. We start at -3 and remember negative number goes to the left 1 2 3 4 5 6. So, that gives you -9. Again, whenever you have subtraction here was the original problem. Change the subtraction and the number right after the subtraction becomes its opposite, okay? And finally, let's work one more problem. changed the problem cuz didn't like it, but again, we have another subtraction problem. So, I'm going to rewrite it. Let's go through this. Is the problem addition? No. Change the subtraction sign to addition and change the number after the subtraction sign to the opposite. So, I'm going to rewrite it. -5 this now becomes an addition and change the negative to positive, okay? And now, remember just act like this is gone and is the problem addition? Yes. Same signs? No. Subtract the smaller number from the larger, keep the sign of the larger. 7 - 5 is equal to 2. And 7 is larger than 5, so it will be positive 2. Now, let's work this on the number line. I'm starting at -5, but now instead of going to the left have positive number so go to the right seven places 1 2 3 4 5 6 7 and so there we go positive two. So hope either the flow chart or the number line helps you in adding and subtracting positive and negative integers. Thanks for watching and remember math uploads new math and science video every day. Please subscribe and share.