Download Subtracting Mixed Fractions with Different Denominators

 Subtracting Mixed Fractions with Different Denominators By John Brooks, M.A. You can find John on Veditz at https://veditz.org/john-­‐brooks You can find John’s ASL Video lesson on Subtracting Mixed Fractions with Different Denominators at: ________________________________________________________________ Hello! Welcome to this video! In this video, we will work on… Subtracting mixed fractions with different denominators. Before we get started, you may be wondering about mixed fractions. Let’s clarify what a mixed fraction means. Suppose you’ve seen some fractions with two numbers. One on top and one on bottom. That is a fraction. But if we have a whole number and a fraction… For example, 2 2/6. The big number of 2 is called a whole number. We have a mixed fraction that includes both a whole number and a fraction. Now that we have clarified what mixed fractions mean… Let’s go through an example of subtracting mixed fractions. But we have an added twist here. Different denominators. This means the numbers below, 6 and 3, are not the same. That leads us to the first step of how to solve this problem. © 2016 Veditz.org and John Brooks What we must do, since 6 and 3 are not the same… We must find the least common denominator. We have to somehow find a way to get 3 to match the other denominator. How? We multiply by 2. So we take the fraction 2/3 and multiply both numbers by 2. What does that give us? 2 times 2 gives us 4. 3 times 2 gives us 6. Now we have matching denominators of 6. We can carry over the fraction of 2/6 since no change needs to be made. It’s important to align the fractions and keep it clean. We have now finished the second step of converting fractions. This was done with the least common denominator of 6. Now the third step we need to do is look at the fractions closely. Are we ready to subtract? No. Why? Because we cannot subtract 4/6 from 2/6. So what do we need to do? Borrow from the whole number. So we would borrow from the whole number, 2. That means we take one away, giving us 1. We add the borrowed amount to the fraction. 6/6 is equal to 1. So we would add 6 to 2, giving us 8/6. But don’t forget to cross out the whole number since we borrowed. 2 becomes 1. Now the fraction portion is finished. We can carry over the 2nd mixed fraction since it has a denominator of 6. Now the last step we take is… Maybe you want to subtract the whole number first… do not do this. We must subtract the fraction first then the whole number. © 2016 Veditz.org and John Brooks So in this case, we have 8/6 minus 4/6. We would subtract 4 from 8. That gives us 4. Our fraction is… 4/6. Then, 1 and 1 cancel each other out so we are left with nothing. So that gives us a final answer of… 4/6. This can also be reduced to 2/3. So now you have an idea of how to subtract mixed fractions with… Different denominators. It’s important to remember to look at the fractions. Are both denominators the same? If not, go ahead and find the least common denominator. Then you should be able to work through the rest of the steps. Thank you for watching! © 2016 Veditz.org and John Brooks