Math 4 · Unit 15: Special numbers · Cambridge Primary Maths Stage 4

Questions

1. 1. Here are four labels: multiple of 5, not a multiple of 5, odd, even. Each label goes in a heading of the sorting diagram. Where does each label go?

   • The first column
   • The second column
   • The first row
   • The second row

   • not a multiple of 5
   • odd
   • even
   • multiple of 5
   Check

2. 2. Imagine colouring all the odd numbers in the grid. The coloured squares make a hidden number. What is it?

   • 21
   • 72
   • 15
   • 12
   Check

3. 3. Look at the number grid. Tick the 3 multiples of 7.

   Tick all the right answers.

   • ☐ 63
   • ☐ 65
   • ☐ 70
   • ☐ 74
   • ☐ 77
   • ☐ 78
   Check

4. 4. Complete: 3 and 7 are ______ of ☐ because 3 × 7 = ☐. And ☐ is a ______ of 3 and 7 because ☐ ÷ 3 = 7 and ☐ ÷ 7 = 3.

   • factors, multiple, and 10 in every box
   • factors, multiple, and 21 in every box
   • multiples, factor, and 37 in every box
   • multiples, factor, and 21 in every box
   Check

5. 5. Put a cross (X) through the number that is in the wrong place. Write it in the correct place.

   Check

6. 6. What are all the factor pairs for 24?

   • 1 × 24, 2 × 12, 3 × 8, 4 × 8
   • 1 × 24, 2 × 12, 3 × 8, 4 × 6
   • 1 × 24, 2 × 12, 4 × 6, 5 × 5
   • 2 × 12, 3 × 8, 4 × 6
   Check

7. 7. Kojo says, 'Nine is a square number.' Is Kojo correct?

   • Yes
   • No
   Check

8. 8. Kofi's number is a multiple of 3, a multiple of 5, odd, and between 20 and 60. What is Kofi's number?

   • 35
   • 45
   • 15
   • 30
   Check

9. 9. Why can't a number ending in 5 be a multiple of 4?

   • Because multiples of 4 end in 4.
   • Because 5 is not a square number.
   • Multiples of 4 are all even, but a number ending in 5 is odd.
   • Because 5 is bigger than 4.
   Check

10. 10. Here is a diagram for sorting numbers. Where does each number go?

    • 64
    • 25
    • 24
    • 65

    • not a square number, odd
    • square number, even
    • not a square number, even
    • square number, odd
    Check

11. 11. What are all the factors of 20?

    • 1, 2, 4, 5, 10, 20
    • 1, 2, 4, 5, 10
    • 20, 40, 60, 80
    • 2, 4, 5, 10
    Check

12. 12. What are all the multiples of 20 that are less than 100?

    • 40, 60, 80
    • 1, 2, 4, 5, 10, 20
    • 20, 40, 60, 80, 100
    • 20, 40, 60, 80
    Check

13. 13. Use four different square numbers to make these calculations correct.

    Fill the blanks with these.

    • 6
    • 4
    • 1
    • 16
    • 3
    • 9
    Check

14. 14. Write the 2-digit odd number that is a multiple of 7: 4☐. What is special about it?

    • 45: it is a multiple of 5
    • 47: it is a multiple of 7
    • 42: it is even
    • 49: it is a square number (7 × 7)
    Check

15. 15. Use the digit cards 3, 4, 5 and 6 once each to make two 2-digit numbers with a total that is a multiple of 6. Which works?

    • 36 and 45
    • 35 and 46
    • 34 and 56
    • 53 and 64
    Check

16. 16. Look at 8, 12, 25 and 40. Why is 8 the odd one out?

    • It is the only multiple of 4.
    • It is the only 1-digit number.
    • It is the only odd number.
    • It is the only even number.
    Check

17. 17. Look at 8, 12, 25 and 40. Why is 12 the odd one out?

    • It is the only number less than 20.
    • It is the only multiple of 3.
    • It is the only even number.
    • It is the only 2-digit number.
    Check

18. 18. Look at 8, 12, 25 and 40. Why is 25 the odd one out?

    • It is the only odd number.
    • It is the only even number.
    • It is the only number bigger than 20.
    • It is the only multiple of 5.
    Check

19. 19. Look at 8, 12, 25 and 40. Why is 40 the odd one out?

    • It is the only number greater than 10.
    • It is the only 1-digit number.
    • It is the only multiple of 3.
    • It is the only number greater than 30.
    Check

20. 20. Use the tree diagram to sort the numbers 18, −24, 27, 19, 14, −21, −5 and −14. In which boxes do they go?

    • −24 box 2, −14 box 1, −21 box 4, −5 box 3, 18 box 6, 14 box 5, 27 box 8, 19 box 7
    • −24 box 1, −14 box 2, −21 box 4, −5 box 3, 18 box 5, 14 box 6, 27 box 7, 19 box 8
    • −24 box 1, −14 box 2, −21 box 3, −5 box 4, 18 box 5, 14 box 6, 27 box 7, 19 box 8
    • −24 box 1, −14 box 2, −21 box 3, −5 box 4, 18 box 6, 14 box 5, 27 box 8, 19 box 7
    Check