# Find the Sum of the GCF and LCM - Set 1

Explanation: The "GCF" and "LCM" are the "Greatest Common Factor" and "Lowest Common Multiple".  The factors and multiples are positive.

Examples: Find the sum of the GCF and LCM of:

12 & 20      Factors of 12: 1, 2, 3, 4, 6 & 12     Factors of 20: 1, 2, 4, 5, 10 & 20     First multiples of 12: 12, 24, 36, 48,  60 & 72        First multiples of 20: 20, 40 & 60       GCF = 4, LCM = 60        Sum of GCF & LCM = 4 + 60 = 64

6 & 15       Factors of 6: 1, 2, 3 & 6        Factors of 15: 1, 3, 5 & 15          First multiples of 6: 6, 12, 18, 24, 30        First multiples of 15: 15, 30 & 45       GCF = 3,     LCM = 30        Sum of GCF & LCM = 3 + 33 = 33

7 & 8         Factors of 7: 1 & 7          Factors of 8: 1, 2, 4 & 8              First multiples of 7: 7, 14, 21, 35, 42, 49 & 56     First multiples of 8: 8, 16, 24, 32, 40, 48 & 56        GCF: 1     LCM: 56    Sum of GCF & LCM = 1 + 56 = 57

Directions: For each problem in this problem set you are to identify the GCF and LCM and find the sum of the GCF and LCM of the given pairs of numbers.  Strive to be able to accomplish the problems with ease and then strive to increase your speed.  Good luck and enjoy the challenge!