Page 3 - Add and Subtract Fractions

Fractions: Addition

& Subtraction

When subtracting fractions

5 Numerator

with different denominators
6 Denominator

3 1
Example: −
5 15

Step 1: Find the Lowest Common Multiple of both Denominators

3 x 1 = 3 3 x 2 = 6 3 x 3 = 9 3 x 4 = 12 3 x 5 = 15 3 x 6 = 18

15 x 1 = 15 15 x 2 = 30 15 x 3 = 45 15 x 4 = 60 15 x 5 = 75 15 x 6 = 90

15 is the Lowest Common Multiple

Calculate

3×3 − 1×1

5×3 15×1

9 1
= −
15 15

8
=
15

Proper Fraction Improper Fraction Mixed Numbers

Numerator is less than Numerator is more than Whole number and a
the denominator. the denominator. fraction combined.

7 2
3
5 5