SUBTRACTING FRACTIONS How to Subtract Fractions Fractions consist of two numbers. The top number is called the numerator. The bottom number is called the denominator. numerator denominator To subtract two fractions with the same denominator: • Subtract the numerators and • Place that difference over the common denominator. Example: Find the difference between 5/9 and 2/9. Subtract the numerators: 5 – 2 = 3 Place the 3 over the common denominator 9, and simplify The result is 3/9 = 1/3 To subtract fractions with different denominators: • Find the Lowest Common Denominator (LCD) of the fractions • Rename the fractions to have the LCD • Subtract the numerators of the fractions • The difference will be the numerator and the LCD will be the denominator of the answer. • Simplify the fraction Example: Find the difference between 3/12 and 2/9. • Determine the Greatest Common Factor of 12 and 9 which is 3 • Either multiply the numbers and divide by the GCF (9*12=108, 108/3=36) - OR - Divide one of the numbers by the GCF and multiply the answer times the other number (12/3=4, 9*4=36) • Rename the fractions to use the Lowest Common Denominator (3/12=9/36, 2/9=8/36) • The result is 9/36 - 8/36 • Subtract the numerators and put the difference over the LCD = 1/36 • Simplify the fraction if possible. In this case it is not possible © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Try This! Find the difference for the following fractions: 3/5 – 2/5 = _______ 9/25 – 11/25 = ________ 2/3 – 9/24 = ________ 4/8 – 6/10 = ________ © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.