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Primary 5 · Mathematics · Factors & Multiples

Factors & Multiples questions for Primary 5 Maths

10 questions to work through online. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.

  • Common factors
  • Common multiples
  • Prime numbers
  • Common factors in context
  • Common multiples in context
  • Counting factors
  • Recognising multiples
0 of 10 answered
Question 1 of 10Common factors
What is the greatest common factor of 36 and 54?
Question 2 of 10Common multiples
What is the smallest common multiple of 6 and 8?
Question 3 of 10Prime numbers
Which of these is a prime number?
Question 4 of 10Prime numbers
Which of these is NOT a prime number?
Question 5 of 10Common factors in context
60 pencils and 48 rulers are packed into identical sets with nothing left over. What is the greatest number of sets possible?
Question 6 of 10Common multiples in context
One light flashes every 9 seconds and another every 12 seconds. They flash together now. After how many seconds will they next flash together?
Question 7 of 10Counting factors
How many factors does 36 have?
Question 8 of 10Recognising multiples
Which of these numbers is a multiple of both 4 and 9?
Question 9 of 10Common factors
What is the greatest common factor of 24 and 42?
Question 10 of 10Prime numbers
How many prime numbers are there between 10 and 20?
Answers and explanations for all 10 questions

Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.

  1. What is the greatest common factor of 36 and 54?

    Answer: 18

    36 = 18 × 2 and 54 = 18 × 3, and nothing larger than 18 divides both.

  2. What is the smallest common multiple of 6 and 8?

    Answer: 24

    Multiples of 6: 6, 12, 18, 24. Multiples of 8: 8, 16, 24. The first they share is 24.

  3. Which of these is a prime number?

    Answer: 29

    29 can only be divided by 1 and itself, so it is prime.

  4. Which of these is NOT a prime number?

    Answer: 51

    51 = 3 × 17, so it has more than two factors and is not prime.

  5. 60 pencils and 48 rulers are packed into identical sets with nothing left over. What is the greatest number of sets possible?

    Answer: 12

    The sets must divide both 60 and 48. Their greatest common factor is 12.

  6. One light flashes every 9 seconds and another every 12 seconds. They flash together now. After how many seconds will they next flash together?

    Answer: 36

    Multiples of 9: 9, 18, 27, 36. Multiples of 12: 12, 24, 36. The first shared is 36 seconds.

  7. How many factors does 36 have?

    Answer: 9

    1, 2, 3, 4, 6, 9, 12, 18 and 36 — 9 factors in all.

  8. Which of these numbers is a multiple of both 4 and 9?

    Answer: 72

    72 = 4 × 18 and 72 = 9 × 8, so it is a multiple of both.

  9. What is the greatest common factor of 24 and 42?

    Answer: 6

    24 = 6 × 4 and 42 = 6 × 7, and nothing larger divides both.

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

    Answer: 4

    11, 13, 17 and 19 are prime; 12, 14, 15, 16, 18 and 20 are not.