How to Add and Subtract Like Fractions

Step-by-Step Guide

1. 1

   Step 1: Determine that you have like fractions.

   Like fractions are fractions that have the same denominator.
   
   The denominator is the number below the fraction bar.
   
   If you do not have like fractions, you cannot use this method.
   
   To learn how to add fractions with unlike denominators, you can read Add Fractions With Unlike Denominators.
   
   For example, 38{\displaystyle {\frac {3}{8}}} and 34{\displaystyle {\frac {3}{4}}} are not like fractions, because they have different denominators.
   
   The fractions 38{\displaystyle {\frac {3}{8}}} and 18{\displaystyle {\frac {1}{8}}} are like fractions, because they have the same denominator (8).
2. 2

   Step 2: Add the numerators of the fractions.The numerators are the numbers above the fraction bar.

   For example, if you are adding 38{\displaystyle {\frac {3}{8}}} and 18{\displaystyle {\frac {1}{8}}}, you would first calculate 3+1=4{\displaystyle 3+1=4}. , Do NOT add the denominators.For example, 38+18=48{\displaystyle {\frac {3}{8}}+{\frac {1}{8}}={\frac {4}{8}}}. , For school work, your instructor will most likely want you to simplify, or reduce your fraction.
   
   To do this, you need to find the largest number that will divide evenly into the numerator and denominator.Divide the numerator and denominator by this number to find the simplified fraction.
   
   For more information on how to do this, read Reduce Fractions.
   
   For example, 4 and 8 can both be divided by 4:4÷4=1{\displaystyle 4\div 4=1}8÷4=2{\displaystyle 8\div 4=2}So, 48{\displaystyle {\frac {4}{8}}}simplifies to 12{\displaystyle {\frac {1}{2}}}.
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   Step 3: Place the sum of the numerators over the original denominator.

4. 4

   Step 4: Simplify if necessary.

Detailed Guide

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