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.

   Esme copies a clue from the board. Factors of 16: 1, 2, 4, 8, 16. Factors of 20: 1, 2, 4, 5, 10, 20. What is the greatest common factor of 16 and 20?

   4
2. 2.

   Jun finds a hint in a book. Multiples of 4: 4, 8, 12, 16. Multiples of 6: 6, 12, 18. What is the least common multiple of 4 and 6?

   12
3. 3.

   Ari races the clock on a number puzzle. What is the least common multiple of 3 and 8?

   24
4. 4.

   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
5. 5.

   Jun has 12 pencils and 28 erasers for the class. Jun puts them into identical supply bags with none left over. What is the greatest number of bags Jun can fill?

   4
6. 6.

   Luz watches two buses. Bus A leaves every 6 minutes and Bus B every 9 minutes. They leave together at 8:00. In how many minutes do they next leave together?

   18
7. 7.

   Noah's garden path has a red stone every 3 feet and a blue stone every 5 feet from the gate. After how many feet is the first spot with both stones?

   15
8. 8.

   Ren factors a sum. The greatest common factor of 12 and 20 is 4. 12 + 20 = 4(3 + 5). What number goes in the blank?

9. 9.

   Tala factors a sum. The greatest common factor of 18 and 27 is 9. 18 + 27 = 9(2 + 3). What number goes in the blank?

10. 10.

    Zee picks a card. Which expression is 12 + 18 with the greatest common factor taken out?

    • 2(6 + 9)
    • 6(2 + 3)
    • 4(3 + 18)