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Why do the denominators have to be the same for both fractions when adding and subtracting?
Wiki User
∙ 12y ago
It makes it easier. So both of the fractions are proportional to each other.
Wiki User
∙ 12y ago
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How do you subtract improper fractions with different denominators?
It's the same thing as adding or subtracting normal fractions - just make sure both fractions have the same denominators (by either multiplying the denominators or simplifying the fraction - whichever the question needs).
Do you have to change the denominators when multiplying fractions?
No. To multiple fractions multiple the numerators together and multiply the denominators together and simplify (by dividing both numerator and denominator of the result by common factors until the only common factor is 1). The denominators only need to be the same when adding or subtracting fractions.
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 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).
Adding mixed numbers with unlike denominators?
First convert the mixed numbers into "top heavy (or "improper) fractions". Now multiply each of the improper fractions by each other - this makes the denominators the same. Now you can add both the fractions together (and cancel down if necessary).
When adding or subtracting fractions what should you do first?
For adding or substracting fractions first of all we should calculate the LCM( Lowest Common Multiplier) of the denominators in both of the fractions.
How do you subtract improper fractions with different denominators?
It's the same thing as adding or subtracting normal fractions - just make sure both fractions have the same denominators (by either multiplying the denominators or simplifying the fraction - whichever the question needs).
Do you have to change the denominators when multiplying fractions?
No. To multiple fractions multiple the numerators together and multiply the denominators together and simplify (by dividing both numerator and denominator of the result by common factors until the only common factor is 1). The denominators only need to be the same when adding or subtracting fractions.
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.
How is subtracting fractions like adding fractions?
You need a common denominator for both.
Do you Add both the numerators and the denominators when adding fractions and mixed numbers?
False [ I THINK ]
How are equivalent fractions used in renaming when subtracting?
When subtracting one fraction to another, one or both fractions are renamed so that they have the same denominators. Then the result of the subtraction is the equal to the subtraction of the numerators divided by the common denominator.
Why are equivalent fractions important when adding and subtracting fractions?
Because to add or subtract two fractions you first have to find equivalent fractions for both which have the same denominator.
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).
Why when adding do you not add the numerator or the denominator?
Do not add the denominators together. Though keep in mind that both denominators must be the same to add to fractions together.
Why is it helpful to find common factors for 2 nummbers?
This can be especially helpful if you are adding or subtracting fractions, so the bottom number on both fractions will be the same
How can knowing the GCF and LCM help you when you add subtract and multiply fractions?
Knowing the LCM will help when adding or subtracting unlike fractions. By finding the LCM of the denominators, (called the lowest common denominator) you can convert unlike to like fractions and proceed with the adding or subtracting. Knowing the GCF helps reduce a fraction. By finding the GCF of the numerator and the denominator and dividing both of them by it, you can reduce a fraction to its lowest terms (simplest form). If the GCF is 1, the fraction is in its simplest form. You can successfully multiply fractions without knowing the GCF or LCM.
