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Find a missing number when you know the mean

Year 6 maths · Fieldbook Learning

Name ______________________ Date __________

Use the mean to find the total, then take away the numbers you know.

  1. The mean of 4 numbers is 5. Here are 3 of them: 7, 4, 4. What is the missing number?
  2. The mean of 3 numbers is 7. Here are 2 of them: 9, 7. What is the missing number?
  3. The mean of 3 numbers is 8. Here are 2 of them: 7, 9. What is the missing number?
  4. The mean of 4 numbers is 10. Here are 3 of them: 10, 14, 15. What is the missing number?
  5. The mean of 5 numbers is 15. Here are 4 of them: 17, 20, 22, 9. What is the missing number?
  6. The mean of 5 numbers is 20. Here are 4 of them: 11, 28, 21, 20. What is the missing number?
  7. The mean of 4 numbers is 14. Here are 3 of them: 11, 12, 15. What is the missing number?
  8. The mean of 4 numbers is 12. Here are 3 of them: 14, 12, 7. What is the missing number?
  9. The mean of 5 numbers is 26. Here are 4 of them: 29, 24, 33, 27. What is the missing number?
  10. The mean of 6 numbers is 12. Here are 5 of them: 7, 10, 16, 15, 11. What is the missing number?
  11. The mean of 5 numbers is 39. Here are 4 of them: 49, 53, 23, 36. What is the missing number?
  12. The mean of 6 numbers is 12. Here are 5 of them: 7, 16, 9, 7, 15. What is the missing number?
  13. The mean of 8 numbers is 55. Here are 7 of them: 78, 65, 56, 63, 36, 73, 66. What is the missing number?
  14. The mean of 7 numbers is 33. Here are 6 of them: 35, 26, 45, 49, 30, 39. What is the missing number?
  15. The mean of 6 numbers is 38. Here are 5 of them: 50, 19, 34, 55, 42. What is the missing number?
  16. The mean of 8 numbers is 16. Here are 7 of them: 21, 23, 24, 14, 11, 16, 18. What is the missing number?
  17. The mean of 10 numbers is 87. Here are 9 of them: 58, 73, 116, 70, 86, 123, 98, 75, 96. What is the missing number?
  18. The mean of 7 numbers is 71. Here are 6 of them: 73, 100, 49, 72, 83, 105. What is the missing number?
  19. The mean of 9 numbers is 64. Here are 8 of them: 65, 64, 48, 34, 56, 32, 60, 73. What is the missing number?
  20. The mean of 7 numbers is 76. Here are 6 of them: 91, 77, 68, 80, 50, 102. What is the missing number?
More free practice: fieldbooklearning.com/au/practice/year-6/find-a-missing-value-given-the-mean/

Play it as a quiz game

20 of these questions as multiple choice, with near-miss wrong answers, ready for Kahoot or Blooket.

  1. Download the game's own question template: in Kahoot, Add question → Import spreadsheet; in Blooket, Create a set → Spreadsheet import.
  2. Click the matching button below, then click the first empty question row of the template and paste.
  3. Save the template (Kahoot needs .xlsx, Blooket .csv) and upload it.
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Answer key: Find a missing number when you know the mean

  1. 5
  2. 5
  3. 8
  4. 1
  5. 7
  6. 20
  7. 18
  8. 15
  9. 17
  10. 13
  11. 34
  12. 18
  13. 3
  14. 7
  15. 28
  16. 1
  17. 75
  18. 15
  19. 144
  20. 64