Greatest common factor, least common multiple

Answer Key - Grade 6 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. 1.

   Bo reads a puzzle card. Factors of 15: 1, 3, 5, 15. Factors of 20: 1, 2, 4, 5, 10, 20. What is the greatest common factor of 15 and 20?

   5
2. 2.

   Kira races the clock on a number puzzle. Multiples of 6: 6, 12, 18, 24, 30. Multiples of 8: 8, 16, 24, 32. What is the least common multiple of 6 and 8?

   24
3. 3.

   Luz solves a number puzzle. Multiples of 3: 3, 6, 9, 12, 15. Multiples of 4: 4, 8, 12, 16. What is the least common multiple of 3 and 4?

   12
4. 4.

   Pia reads a puzzle card. What is the greatest common factor of 8 and 20?

   4
5. 5.

   Zee finds a hint in a book. What is the least common multiple of 6 and 10?

   30
6. 6.

   Bo solves a number puzzle. What is the least common multiple of 5 and 6?

   30
7. 7.

   Esme has 18 paper plates and 24 paper cups for a party. Esme makes identical party sets with no plates or cups left over. What is the greatest number of sets Esme can make?

   6
8. 8.

   Paper plates come in packs of 6 and paper cups in packs of 8. Milo wants the same number of plates and cups. What is the least number of plates Milo can buy?

   24
9. 9.

   Pia factors a sum. The greatest common factor of 10 and 15 is 5. 10 + 15 = 5(2 + 3). What number goes in the blank?

10. 10.

    Bo picks a card. Which expression is 20 + 32 with the greatest common factor taken out?

    • 5(4 + 32)
    • 4(5 + 8)
    • 2(10 + 16)