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Why do fractions need common denominators before you add or subtract them?
Wiki User
∙ 7y ago
That's for the same reason that you can't directly add hundreds and thousands, for example; you would get the wrong results. Or, if you add grams and kilograms, or meters and millimeters, you'll similarly get wrong results. As an example, it makes sense to add 5 meters + 3 meters = 8 meters. But if you have the equivalent 5 meters + 3000 mm, if you just add the numbers you get a nonsensical answer; and as to the units - what unit should you use? There is simply no way to get a sensible answer, without first converting everything to the same unit.
Similarly, with fractions, if you try to add, say, 1/2 and 3/5, you have "pieces" (halves, and fifths, in this case) of different size; after you convert them to equivalent pieces of the same size, it makes sense to add, subtract, or compare.
Wiki User
∙ 7y ago
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How do u subtract fractions?
multiply the fractions until they have common denominators and then subtract them
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 without alike denominators?
Convert unlike fractions to equivalent fractions with common denominators by finding the LCM of the denominators.
How do you subtract fractions with unequal denominators?
by finding the common denominator of the fractions
What is the process of subtracting fractions?
If the denominators are the same, subtract the numerators. If the denominators are different, convert them to equivalent fractions with a common denominator and subtract the numerators.
How do u subtract fractions?
multiply the fractions until they have common denominators and then subtract them
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.
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 without alike denominators?
Convert unlike fractions to equivalent fractions with common denominators by finding the LCM of the denominators.
How do you subtract fractions with unequal denominators?
by finding the common denominator of the fractions
What is the process of subtracting fractions?
If the denominators are the same, subtract the numerators. If the denominators are different, convert them to equivalent fractions with a common denominator and subtract the numerators.
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.
What do you not have to think about when you add or subtract fractions?
Whether the denominators are common or not.
How is finding the LCM revelant when adding and subtracting fractions?
To add and subtract fractions, you need common denominators. To find the common denominator, find the LCM of the denominators you wish to add or subtract.
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.
How do you subtract Fractions with models unlike denominators?
The denominators need to be the same for subtraction. Find the Least Common Denominator for both items and then subtract.
How do you use prime factorization to subtract fractions in math?
Finding the prime factorizations of the denominators will help you find the least common denominator. Converting to equivalent fractions with like denominators will allow you to subtract them successfully.
