Subtracting Mixed Numbers Unlike Denominators Math with Mr J

Welcome to Math with Mr. In this video, we're going to discuss how to subtract mixed numbers. And as you can see, there are two problems on your screen that we're going to go through in order to get this down. So, let's jump right in to number one. And for number one, we have 5 and 3/4 minus 2 and 1/2. So, the first thing like to do when subtracting or adding mixed numbers, like to rewrite the problem vertically, up and down. So, I'm going to underneath my original problem, rewrite 5 and 3/4 minus 2 and 1/2. Now, notice have my fractional part of the mixed numbers lined up and the whole number part of the mixed numbers lined up. Now, what you need to do, we need to subtract the fractional part first. Now, just like when we add or subtract fractions, we need common denominator. And obviously, denominator of 4 and 2, we don't have the same denominator. So, we're going to need to rename both these mixed numbers, the fractional part of the mixed numbers, with common denominator. So, let's think, what's going to be our common denominator for 4 and 2? Hopefully, you're thinking four. So, let's rename these mixed numbers. Well, 5 and 3/4 already has denominator of 4. So, we can keep it as is. Now, 2 and 1/2 though, we're going to need to rename. So, let's think. 2 * 2 gives me that denominator of 4. So, need to do the same thing to the top in order to properly rename. so, we would do 1 * 2 is 2. Now, we have our problem rewritten with common denominator. Now, subtract the fractional parts and then the whole number parts. So, 3/4 - 2/4, well, 3 - 2 is 1. Keep our denominator of 4 the same. And then do 5 - 2 which gives us three. Always look to see if the answer can be simplified, the fractional part. 1/4, 1/4 is in lowest terms, so we are done. The solution or answer to number one is 3 and 1/4. Let's take look at number two. Let's rewrite the problem vertically, which means which means up and down. 7 and 1/3 minus and 5/6. All right. Let's do the fractional part first. We do not have common denominator, so we will need to rename with common denominator. So, 3 and 6, let's think. Hopefully, we're thinking common denominator of 6. So, 7 and how many sixths? Well, 3 * 2 is 6. 1 * 2 is 2. Minus 3, 5/6 already has denominator of 6. So, there is our rewritten problem. So, let's subtract the fractional part. 2/6 - 5/6. Well, we can't do that because we cannot do 2 - 5. So, just like whole number subtraction problem, we need to borrow to be able to do the fractional part of this problem. So, how you do that with mixed numbers, we're going to borrow one from this seven. And it's going to turn to six. And we're going to add one whole to that 2/6. Now, I'm going to write one whole as 6 over 6 so can add it to that fractional part. They need common denominator in order to add that whole there. So, again, 6 over 6 is one whole. just put it with denominator of 6. So, now we have six wholes, right? And then 2 + 6 is 8. Keep my denominator of 6. Subtract 3 and 5/6. Now, we can do 8 - 5 is 3. Keep my denominator of 6. And then we have 6 - 3 is 3. Check to see if we can simplify the fractional part, and we can. common factor between 3 and 6 is 3, so can divide by 3 to get the fractional part in lowest terms. And this actually turns out to be 3 and 1/2. That would be our final answer there. So, there you have it. There's how you subtract mixed numbers. Rewrite the problem vertically. See if you need common denominator. Rename if you do. Then go ahead and subtract the fractional part, then the whole number part. Thanks so much for watching. Until next time. Peace.