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Adding and Subtracting Fractions
6,245 ReadsAdding and subtracting fractions is just as easy. It's the same idea once you have the same denominator, you can just add or subtract the numerators, keeping the denominator the same.
Adding Fractions
Example-1
Since the denominators are the same, we can just add 2 + 4 to get 6.
Careful don't add the denominators by accident!
A quick way to check yourself is to make sure the denominator of your answer is the same as the denominators of the two fractions you add or subtract.
Subtracting Fractions
Subtracting fractions is just like adding them.
Example-2
We have the same denominator, so we can subtract 9 - 4 to get 5.
Remember, when the denominators aren't the same, we just find the least common denominator following the steps we learned earlier.
Example-3
This question is asking us to compare and then add two fractions.
List out multiples and look for the first one that's the same for both numbers.
3: 3, 6, 9, 12, 15
5: 5, 10, 15, 20
Then convert each fraction with same denominator.
Now, to compare the fractions, we just compare 5 and 6.
6 is bigger.
So, Kenny painted more of the fence on Tuesday.
Finally, we add the two fractions to see how much he painted on both days.
5 + 6 = 11, and remember to keep the denominator the same.
Intro to Fractions
- Fractions represent parts of whole numbers
- Numerator (number on top) represents how many parts of the whole you have
- Denominator (number on the bottom) represents how many equal parts the whole is divided into.
- Least Common Denominator: To perform some operations on fractions, you'll need to make sure their denominator is the same. Follow these three steps:
- List out the multiples of each denominator
- Find the smallest multiple the two denominators have in common; this is the least common denominator.
- Convert each fraction so it has this denominator by multiplying the numerator and the denominator by the same number.
