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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 379 · 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.?204 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.4?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 86 and take away the sum of its digits. What do you get?
  4. 4.Take 56 and take away the sum of its digits. What do you get?
  5. 5.Take 49 and take away the sum of its digits. What do you get?
  6. 6.?244 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 52 and take away the sum of its digits. What do you get?
  8. 8.17?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?044 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 13 and take away the sum of its digits. What do you get?
  11. 11.?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.846? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.888? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.41?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.11?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 21 and take away the sum of its digits. What do you get?
  17. 17.46?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.24?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 97 and take away the sum of its digits. What do you get?
  20. 20.2?11 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 72 and take away the sum of its digits. What do you get?
  22. 22.Take 79 and take away the sum of its digits. What do you get?
  23. 23.399? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.64?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.29?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 83 and take away the sum of its digits. What do you get?
  27. 27.Take 81 and take away the sum of its digits. What do you get?
  28. 28.Take 96 and take away the sum of its digits. What do you get?
  29. 29.5?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 85 and take away the sum of its digits. What do you get?
  31. 31.509? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?785 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.52?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 62 and take away the sum of its digits. What do you get?
  35. 35.?490 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.24?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?188 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?581 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 35 and take away the sum of its digits. What do you get?
  40. 40.380? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 3
  2. 4
  3. 72
  4. 45
  5. 36
  6. 8
  7. 45
  8. 1
  9. 1
  10. 9
  11. 2
  12. 9
  13. 3
  14. 3
  15. 5
  16. 18
  17. 8
  18. 3
  19. 81
  20. 5
  21. 63
  22. 63
  23. 6
  24. 3
  25. 1
  26. 72
  27. 72
  28. 81
  29. 9
  30. 72
  31. 4
  32. 7
  33. 9
  34. 54
  35. 5
  36. 5
  37. 1
  38. 4
  39. 27
  40. 7

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