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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 858 · 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.?752 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?687 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?123 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.631? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 78 and take away the sum of its digits. What do you get?
  6. 6.?158 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?313 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.86?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 79 and take away the sum of its digits. What do you get?
  10. 10.4?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.32?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?989 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 15 and take away the sum of its digits. What do you get?
  14. 14.6?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 61 and take away the sum of its digits. What do you get?
  16. 16.5?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.6?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?451 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.26?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 54 and take away the sum of its digits. What do you get?
  21. 21.32?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.39?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.166? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?334 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?721 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.860? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.460? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 20 and take away the sum of its digits. What do you get?
  29. 29.Take 42 and take away the sum of its digits. What do you get?
  30. 30.20?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 39 and take away the sum of its digits. What do you get?
  32. 32.Take 88 and take away the sum of its digits. What do you get?
  33. 33.?962 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.18?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.289? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.229? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.803? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.71? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.74?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?070 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 4
  2. 6
  3. 3
  4. 8
  5. 63
  6. 4
  7. 2
  8. 8
  9. 63
  10. 2
  11. 5
  12. 1
  13. 9
  14. 3
  15. 54
  16. 7
  17. 7
  18. 8
  19. 9
  20. 45
  21. 9
  22. 6
  23. 5
  24. 8
  25. 8
  26. 4
  27. 8
  28. 18
  29. 36
  30. 8
  31. 27
  32. 72
  33. 1
  34. 5
  35. 8
  36. 5
  37. 7
  38. 1
  39. 2
  40. 2

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