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When subtracting fractions why must there be a common denominator?
Wiki User
∙ 10y ago
To get the correct answer. Look at 1/2 - 1/3. Most people can't tell what the answer is by looking at it. But if you rewrite it as 3/6 - 2/6, it's easy to see that the answer is 1/6.
Wiki User
∙ 10y ago
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When adding or subtracting fractions you must get a?
A Common Denominator
What are the step in subtracting disimilar fraction?
Same as for adding: If the denominators are not equal, you must first find a common denominator, then convert both fractions to that common denominator.
What did you learn from adding and subtracting fractions?
I learned to always change the denominators before adding or subtracting the numerators. You must always have a common denominator before adding or subtracting.
What information does the least common multiple of two numbers provide in a problem?
When adding or subtracting fractions with different denominators the lowest common denominator is needed and is found by finding the lowest common multiple of the denominators.
What is the difference between a least common multiple and a least common denominator?
The Least (or Lowest) Common Multiple (LCM) is the smallest number that is a multiple of both numbers. For example: the LCM of 10 and 4 is 20, because both 10 and 4 go into 20 and 20 is the smallest number both 10 and 4 can go into. To be able to add or subtract fractions they must have the same denominator. If the denominators are different then the fractions must first be converted into equivalent fractions with a common denominator; any common denominator can be used, but by using the Least Common Multiple of the denominators as the new denominator it keeps the numbers smaller; this smallest denominator is known as the Least Common Denominator Thus the Least Common Denominator is the Least Common Multiple of the denominators of two (or more) fractions (used when adding or subtracting fractions with different denominators). As the Least Common Multiple is used most often with adding or subtracting fractions, it is often referred to as the Least Common Denominator (because the numbers being considered are usually denominators of fractions).
When adding or subtracting fractions you must get a?
A Common Denominator
What are the step in subtracting disimilar fraction?
Same as for adding: If the denominators are not equal, you must first find a common denominator, then convert both fractions to that common denominator.
What did you learn from adding and subtracting fractions?
I learned to always change the denominators before adding or subtracting the numerators. You must always have a common denominator before adding or subtracting.
how to rename fractions using LCM?
When adding or subtracting fractions with different denominators their lowest common denominator must be found first by using the LCM of their denominators
What does the common denominator mean?
the bottom number in a fraction. e.g. in 3/6, the common denominator would be 6. in 45/78, it would be 78. the common denominator must be the same in both fractions when adding or subtracting them from/ to each other.
What information does the least common multiple of two numbers provide in a problem?
When adding or subtracting fractions with different denominators the lowest common denominator is needed and is found by finding the lowest common multiple of the denominators.
What is the difference between a least common multiple and a least common denominator?
The Least (or Lowest) Common Multiple (LCM) is the smallest number that is a multiple of both numbers. For example: the LCM of 10 and 4 is 20, because both 10 and 4 go into 20 and 20 is the smallest number both 10 and 4 can go into. To be able to add or subtract fractions they must have the same denominator. If the denominators are different then the fractions must first be converted into equivalent fractions with a common denominator; any common denominator can be used, but by using the Least Common Multiple of the denominators as the new denominator it keeps the numbers smaller; this smallest denominator is known as the Least Common Denominator Thus the Least Common Denominator is the Least Common Multiple of the denominators of two (or more) fractions (used when adding or subtracting fractions with different denominators). As the Least Common Multiple is used most often with adding or subtracting fractions, it is often referred to as the Least Common Denominator (because the numbers being considered are usually denominators of fractions).
When adding or subtracting fractions do you have to have the numerator the same or denominator?
The denominators must be the same, the numerators can be different.
Do you ever have to simplify if you find the LCD when subtracting fractions?
No because in order to subtract or add fractions the denominator of the fractions must be the same and if they are not then the lowest common denominator of the fractions must be found. Having subtracted or added the fractions then it may be possible to simplify the result.
Is it always necessary to find the least common denominator to compare the sizes of fractions?
When comparing fractions you must find a common denominator; by finding the least common denominator it will keep the numbers (numerators and denominator) smaller .
When adding fractions what you always must do is find the?
Common denominator
Why do fractions need a common denominator when adding subtracting?
In order to add or subtract one fraction from another, they must have a common denominator, or the same denominator. That's because it's impossible to add two fractions that have a different number of parts.
