How to Add and Subtract Fractions
Write out your equation., Add the numerators together., Leave the denominator alone., Come up with your answer.
Step-by-Step Guide
-
Step 1: Write out your equation.
If the denominator of the two fractions that you are adding or subtracting is the same, put the same number once as the denominator for your answer.
In other words, 1/5 and 2/5 does not need to be written as 1/5 + 2/5 = ? It can be written as 1+2/5 = ?.
The denominator is the same, so it can be written only once.
Both numerators then go on top. -
Step 2: Add the numerators together.
The "numerator" is the top number of any fraction.
If we take the above example, 1/5 and 2/5, 1 and 2 are our numerators.
Whether you have it written 1/5 + 2/5 or 1+2/5, you answer should be the same: 3! After all, 1 + 2 =
3. , Since you're working with one constant denominator, don't do anything with it! Don't add, subtract, multiply, or divide.
Just leave it be.
So, using the same example, our denominator is
5.
That's it! That's the bottom number of our fraction.
That's half the answer already! , Now, all you do is write out your numerator and your denominator! If you've followed the above example, you'll find that the answer to this problem is 3/5.
What was your numerator?
3.
The denominator?
5.
Therefore, 1/5 + 2/5, or 1+2/5, equals 3/5. -
Step 3: Leave the denominator alone.
-
Step 4: Come up with your answer.
Detailed Guide
If the denominator of the two fractions that you are adding or subtracting is the same, put the same number once as the denominator for your answer.
In other words, 1/5 and 2/5 does not need to be written as 1/5 + 2/5 = ? It can be written as 1+2/5 = ?.
The denominator is the same, so it can be written only once.
Both numerators then go on top.
The "numerator" is the top number of any fraction.
If we take the above example, 1/5 and 2/5, 1 and 2 are our numerators.
Whether you have it written 1/5 + 2/5 or 1+2/5, you answer should be the same: 3! After all, 1 + 2 =
3. , Since you're working with one constant denominator, don't do anything with it! Don't add, subtract, multiply, or divide.
Just leave it be.
So, using the same example, our denominator is
5.
That's it! That's the bottom number of our fraction.
That's half the answer already! , Now, all you do is write out your numerator and your denominator! If you've followed the above example, you'll find that the answer to this problem is 3/5.
What was your numerator?
3.
The denominator?
5.
Therefore, 1/5 + 2/5, or 1+2/5, equals 3/5.
About the Author
Janice Miller
Writer and educator with a focus on practical lifestyle knowledge.
Rate This Guide
How helpful was this guide? Click to rate: