Adding and Subtracting Fractions To add or subtract two fractions that are written with the same denominator (the number on the bottom), simply add or subtract the numerators (the numbers on the top). For example, If the fractions have different denominators, rewrite them first as fractions with the same denominator. (One way to do this is to use a Giant One.) Below are examples of adding and subtracting two fractions with different denominators. Addition example: Subtraction example: Using algebra to write the general method:

ADDITION AND SUBTRACTION OF FRACTIONS Before fractions can be added or subtracted, the fractions must have the same denominator, that is, a common denominator.

2.Find the LCM of the denominators 2 and 5 Multiples of 2=2, 4, 6, 8, 10 Multiples of 5=5, 10, 15, 20 The LCM of 2 and 5 is 10.

2.Find the LCM of the denominators 5 and 3 Multiples of 3=3, 6, 9, 12, 15, 18 Multiples of 5=5, 10, 15, 20 The LCM of 3 and 5 is 15.