Adding and Subtracting Fractions Worksheet
Generate unlimited practice problems with a guaranteed-correct answer key.
20
12
Choose “Save as PDF” in the print dialog to download
Adding and Subtracting Fractions Worksheet
Name:Date:Class:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
worksheetpress.comSeed: k3n9wq
Worked Example
Problem: 2/3 + 3/4
- Find the LCD of 3 and 4.— List multiples of 3: 3, 6, 9, 12. List multiples of 4: 4, 8, 12. The least common denominator is 12.
- Convert each fraction to an equivalent fraction with denominator 12.— 2/3 = 8/12 (multiply top and bottom by 4). 3/4 = 9/12 (multiply top and bottom by 3).
- Add the numerators, keeping the denominator.— 8/12 + 9/12 = 17/12.
- Convert the improper fraction to a mixed number and simplify.— 17 ÷ 12 = 1 remainder 5, so 17/12 = 1 5/12. The fraction 5/12 is already in lowest terms.
Answer: 1 5/12
Frequently Asked Questions
Fractions represent parts of a whole, and the denominator tells you how many equal parts the whole is divided into. You can only directly add parts that are the same size — a common denominator ensures you are counting the same-sized pieces.
Multiply both denominators together — this always works, though it may not give the least common denominator (LCD). For cleaner answers, find the LCD by listing multiples of each denominator until you find the smallest one they share.
No — the denominator stays the same once you have a common denominator. You only add the numerators. For example, 1/5 + 2/5 = 3/5, not 3/10.
Always simplify unless the problem specifies otherwise. Divide the numerator and denominator by their GCF. Also convert any improper fraction result to a mixed number unless the problem asks for an improper fraction.