The least common denominator of a pair of fractions is the least common multiple of the denominators of those fractions. Examples 1/2 + 1/3 can be written in terms of the denominator 6 = 2*3 3/6 + 2/6 1/6 + 3/10 can be written in terms of the denominator 30 = 3*2*5 5/30 + 9/30 The least common multiple of two numbers is their product divided by their greatest common factor. In the last example, the greatest common factor of 6 and 10 is 2, so the LCM[6, 10] = 6*10/2 = 60/2 = 30 In the first example, 2 and 3 have no common factor (except 1).
