Math 5 · Unit 3: Numbers and sequences · Cambridge Primary Maths Stage 5

Questions

1. 1. Which is a prime number?

   • 21
   • 13
   • 15
   • 9
   Check

2. 2. Which is a composite number?

   • 17
   • 21
   • 2
   • 23
   Check

3. 3. Is 1 a prime number?

   • Yes
   • No
   Check

4. 4. What is the only even prime number?

   • 6
   • 2
   • 0
   • 4
   Check

5. 5. What are the factors of 12?

   • 1, 12
   • 1, 2, 3, 4, 6, 12
   • 1, 2, 3, 4, 12
   • 2, 3, 4, 6
   Check

6. 6. How many prime numbers are between 10 and 20?

   • 4
   • 2
   • 5
   • 3
   Check

7. 7. Which number is prime?

   • 39
   • 29
   • 33
   • 27
   Check

8. 8. Is 51 prime?

   • Yes
   • No
   Check

9. 9. Which is a factor of 18?

   • 4
   • 7
   • 6
   • 5
   Check

10. 10. Which number has exactly 3 factors?

    • 8
    • 10
    • 6
    • 9
    Check

11. 11. What is the smallest prime number?

    • 0
    • 3
    • 2
    • 1
    Check

12. 12. What is the largest prime less than 30?

    • 23
    • 29
    • 31
    • 27
    Check

13. 13. Which pair of primes adds to 20?

    • 9 and 11
    • 1 and 19
    • 5 and 15
    • 7 and 13
    Check

14. 14. A number has factors 1, 2, 4, 8. What is it?

    • 4
    • 8
    • 2
    • 16
    Check

15. 15. Which is NOT a factor of 24?

    • 5
    • 3
    • 8
    • 4
    Check