answersLogoWhite

0


Best Answer

Because the answers will be wrong when adding or subtracting them if they don't have a common denominator.

User Avatar

Wiki User

8y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why do fractions need a common denominator before you add or subtract?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Do you need a common denominator for all fractions before doing the order of operations?

You DO need a common denominator to add, subtract, or compare fractions. You DO NOT need a common denominator to multiply or divide fractions.


How do you minnous fractions?

Subtracting fractions is similar to adding fractions. If the fractions have the same denominator, you subtract the numerators. If the fractions have different denominators, you have to convert to a common denominator first.Subtracting fractions is similar to adding fractions. If the fractions have the same denominator, you subtract the numerators. If the fractions have different denominators, you have to convert to a common denominator first.Subtracting fractions is similar to adding fractions. If the fractions have the same denominator, you subtract the numerators. If the fractions have different denominators, you have to convert to a common denominator first.Subtracting fractions is similar to adding fractions. If the fractions have the same denominator, you subtract the numerators. If the fractions have different denominators, you have to convert to a common denominator first.


How do you subtract fractions when denominator is different?

By finding the lowest common denominator of the fractions.


How do subtract two fractions with different denominator?

First find the lowest common denominator and then adjust the fractions accordingly before subtracting the numerators


When do you need a common denominator?

The denominators must be the same before you can add or subtract fractions.


How do you subtract fractions in simplest form?

You first need to find a common denominator, not necessarily the least common denominator. Next, you rename the fractions according to the common denominator. Only then can you subtract the fractions. After subtraction you should simplify the answer.


Why do you need a common denominator?

Common Denominator means that the denominators in two (or more) fractions are common, or the same. The common denominator is important because before you can add or subtract fractions, the fractions need to have a common denominator.Sometimes fractions have different denominators, like 2/3 and 3/4. If you want to add or subtract them, they need to have the same denominator. In order to do that, you find a common denominator which is the same thing as a common multiple, only with denominators.


What you need to add or subtract fractions?

You need a common denominator in order to add or subtract fractions.


How do you subtract fractions with unequal denominators?

by finding the common denominator of the fractions


Do you have to find a common denominator to subtract fractions?

Yes.


How do you add or subtract dissimilar fractions?

You first convert them to similar fractions, i.e., to fractions that have the same denominator.* Step one: find a common denominator.* Step two: convert both fractions to equivalent fractions that have that denominator.


When you subtract fractions do you subtract the denominator?

No. If the denominators are the same, you subtract the numerators. If the denominators are different you have to find the least common denominator.