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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 794 · 40 questions
TalentJR

The trick (Digits add to the 9 table): Add the digits you can see. Find the next number in the 9 table (9, 18, 27 …) above that total. The hidden digit is the difference. (Any number minus its digit sum is in the 9 table too.)

NameDateTime takenScore ___ / 40
  1. 1.440? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 25 and take away the sum of its digits. What do you get?
  3. 3.75? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?290 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.2?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 71 and take away the sum of its digits. What do you get?
  7. 7.70?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.8?59 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.11?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 30 and take away the sum of its digits. What do you get?
  11. 11.310? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?385 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.40?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.791? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 63 and take away the sum of its digits. What do you get?
  16. 16.Take 72 and take away the sum of its digits. What do you get?
  17. 17.Take 55 and take away the sum of its digits. What do you get?
  18. 18.Take 97 and take away the sum of its digits. What do you get?
  19. 19.86?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 15 and take away the sum of its digits. What do you get?
  21. 21.5?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.77? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.52?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?543 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?874 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?849 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?587 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 49 and take away the sum of its digits. What do you get?
  29. 29.6?43 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?834 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 65 and take away the sum of its digits. What do you get?
  33. 33.706? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 64 and take away the sum of its digits. What do you get?
  35. 35.119? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?439 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 46 and take away the sum of its digits. What do you get?
  38. 38.192? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?470 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.3?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 1
  2. 18
  3. 6
  4. 7
  5. 6
  6. 63
  7. 7
  8. 5
  9. 7
  10. 27
  11. 5
  12. 2
  13. 3
  14. 1
  15. 54
  16. 63
  17. 45
  18. 81
  19. 5
  20. 9
  21. 7
  22. 4
  23. 4
  24. 6
  25. 8
  26. 6
  27. 7
  28. 36
  29. 5
  30. 5
  31. 3
  32. 54
  33. 5
  34. 54
  35. 7
  36. 2
  37. 36
  38. 6
  39. 7
  40. 6

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