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Why do fractions need to have a common denominator before you add or subtract them?
Wiki User
∙ 6y ago
The denominator of a fraction tells you the relative size of the pieces. For instance, 1/2 is bigger than 1/4 because it only takes 2 pieces to make a whole, as opposed to 4 pieces to make a whole. One might connect the need for a common denominator to the need for having common units before adding or subtracting (you wouldn't add 12 inches to 12 feet and get 24 for an answer). Therefore, the reason fractions need a common denominator before adding or subtracting is so that the number of pieces you are adding/subtracting are all the same size. By the way, the numerator of a fraction just tells you how many pieces you have of that size.
Because it's easier to get the correct answer this way. Example: 1/3 + 1/4. Without a common denominator, what do you think the answer would be? 1/7? 2/7? 11/34?
The correct answer is 7/12, which can most easily be found by converting 1/3 to 4/12 and 1/4 to 3/12.
Wiki User
∙ 6y ago
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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.
When do you need a common denominator?
The denominators must be the same before you can add or subtract fractions.
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 different denominators?
By finding their lowest common denominator by means of their lowest common multiple
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.
Why do fractions need a common denominator before you add or subtract?
Because the answers will be wrong when adding or subtracting them if they don't have a common denominator.
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.
