Prime factors and perfect squares

Answer Key - Grade 6 Math Worksheet - Building Confidence

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

1. 1.

   Bo picks a card. Which number is the prime number?

   • 1
   • 15
   • 11
   • 14
2. 2.

   Esme is stuck on a riddle: only one of these numbers is prime. Which one is it?

   • 10
   • 13
   • 1
   • 21
3. 3.

   Jun finds a riddle in a book. Which number has just two factors, itself and one?

   • 27
   • 16
   • 1
   • 17
4. 4.

   Milo builds a factor tree for 20. You can type 5 × 5 × 7 or 5^2 × 7. What is 20 as a product of primes?

   2, 2, 5
5. 5.

   Noah picks a card. Which one shows 28 as a product of primes?

   • 1 × 2 × 2 × 7
   • 4 × 7
   • 2 × 7
   • 2 × 2 × 7
6. 6.

   Tala picks a card. Which one shows 30 as a product of primes?

   • 5 × 6
   • 1 × 2 × 3 × 5
   • 2 × 3 × 5
7. 7.

   Jun starts a factor tree for 27 with 27 = 3 × 9. After finishing the tree, what is 27 as a product of primes?

   3, 3, 3
8. 8.

   Luz starts a factor tree for 32 with 32 = 4 × 8. After finishing the tree, what is 32 as a product of primes?

   2, 2, 2, 2, 2
9. 9.

   Noah reads 4² in a puzzle. What is 4²?

   16
10. 10.

    Ren picks a card. Which of these is a perfect square?

    • 20
    • 15
    • 16
    • 18