Adding and Subtracting Fractions

With this article you’ll learn to master adding and subtracting fractions. The following topics appeared 37 times in the last final exams:

Explanation

Definition

Adding and subtracting fractions is an important skill in mathematics. To add or subtract fractions, they must have the same denominator. If the denominators differ, the fractions must first be expanded. Afterwards, simplifying the fraction helps bring it to its simplest form. Concepts like expanding fractions and fraction expansion are also part of this.

\frac{a}{b} + \frac{c}{b} = \frac{a + c}{b}

Procedure

Example: \frac{2}{5} + \frac{1}{5} = \frac{3}{5}.

Example: Expand \frac{1}{2} with 3: \frac{1}{2} = \frac{3}{6}.

Example: Simplify \frac{4}{8} = \frac{1}{2}.

Missunderstandings

Common Errors
  • It is often forgotten to find the common denominator before adding or subtracting.
  • It is mistakenly only the numerator that is multiplied when expanding and not the denominator.
  • Often the largest possible divisor is not used when simplifying.

Problems

1 / 3
Add the fractions
\frac{1}{4} and \frac{2}{4}
2 / 3
Add the fractions
\frac{1}{3} and \frac{1}{4}
3 / 3
Calculate and simplify:
\frac{5}{6} - \frac{1}{4}
rockettutor.com

Start now & improve your maths grades! 🚀

Cancel your trial online at any time

4.62 / 5.0 · 100,000+ students are already improving their grades with us

Get to better maths grades faster — start free today.

Free to try. No credit card. You're in within a few clicks.