Greatest common factor, least common multiple

Answer Key - Grade 6 Math Worksheet

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

1. 1.

   Esme races the clock on a number puzzle. What is the greatest common factor of 28 and 42?

   14
2. 2.

   Jun solves a number puzzle. What is the greatest common factor of 30 and 45?

   15
3. 3.

   Luz reads a puzzle card. What is the greatest common factor of 27 and 45?

   9
4. 4.

   Milo copies a clue from the board. What is the greatest common factor of 42 and 56?

   14
5. 5.

   Pia reads a puzzle card. What is the least common multiple of 5 and 8?

   40
6. 6.

   Tala finds a hint in a book. What is the least common multiple of 4 and 12?

   12
7. 7.

   Esme tracks two bus routes. One leaves the depot every 8 minutes and the other every 10 minutes. Both leave at 6:00 a.m. In how many minutes do they next leave together?

   40
8. 8.

   Pia rewrites a sum. Write 30 + 50 as the greatest common factor times a sum. What number goes in front of the parentheses?

   10
9. 9.

   Tala picks a card. Which expression is 36 + 54 with the greatest common factor taken out?

   • 2(18 + 27)
   • 18(2 + 54)
   • 4(9 + 54)
   • 18(2 + 3)
10. 10.

    Zee picks a card. Which expression is 45 + 75 with the greatest common factor taken out?

    • 9(5 + 75)
    • 15(3 + 5)
    • 15(3 + 75)
    • 3(15 + 25)