# PCSR REVIEW SERIES WEEK 2: Addition and Subtraction of Fractions

PCSR REVIEW SERIES for October 2016

Week 2: Addition and Subtraction of Fractions

In **Week 1** of our PCSR Review Series , we have learned how to get the Least Common Multiple (LCM) and Greatest Common Divisor (GCD) of two or more numbers. The LCM is used to add and subtract dissimilar fractions. To add or subtract fractions, you have to get the LCM of their denominator and convert them to similar fractions.

The GCD is used for converting fractions to lowest terms. In converting fractions to lowest terms, you have to get the GCD of the numerator and denominator of a fraction, and divide both the numerator and the denominator by the GCD.

There are two more skills you need to know: to convert improper fractions to mixed fractions. Most of the time, final answers are required to be in mixed fractions. Links to tutorials on how to do it are included below.

**Articles**

- A Gentle Introduction to Fractions
- How to Convert Mixed Fractions to Improper Fractions
- How to Convert Improper Fractions to Mixed Fractions
- How to Add Fractions
- How to Subtract Fractions

**Videos**

- Converting Mixed Fractions to Improper Fractions
- Converting Improper Fractions to Mixed Fractions
- How to Add Similar Fractions: Tutorial 1, Tutorial 2
- How to Add Dissimilar Fractions: Tutorial 1, Tutorial 2, Tutorial 3
- How to Subtract Similar Fractions: Subtracting Similar Fractions
- How to Subtract Dissimilar Fractions: Tutorial 1, Tutorial 2

**More… **

If you have time and your internet is fast, I suggest that you watch the entire **fraction series** (21 videos):