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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 763 · 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. 1.294? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 74 and take away the sum of its digits. What do you get?
  3. 3.8?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?669 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.587? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 82 and take away the sum of its digits. What do you get?
  7. 7.861? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.263? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.8?31 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.5?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.2?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 76 and take away the sum of its digits. What do you get?
  13. 13.8?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.4?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.2?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.394? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.3?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.6?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 42 and take away the sum of its digits. What do you get?
  20. 20.7?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 89 and take away the sum of its digits. What do you get?
  22. 22.756? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.5?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 11 and take away the sum of its digits. What do you get?
  25. 25.Take 83 and take away the sum of its digits. What do you get?
  26. 26.716? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.6?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.2?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.4?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.412? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 53 and take away the sum of its digits. What do you get?
  32. 32.17?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 33 and take away the sum of its digits. What do you get?
  34. 34.Take 73 and take away the sum of its digits. What do you get?
  35. 35.25?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 91 and take away the sum of its digits. What do you get?
  37. 37.?838 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.306? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.7?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?859 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. 63
  3. 5
  4. 6
  5. 7
  6. 72
  7. 3
  8. 7
  9. 6
  10. 5
  11. 9
  12. 63
  13. 3
  14. 6
  15. 4
  16. 2
  17. 3
  18. 5
  19. 36
  20. 3
  21. 72
  22. 9
  23. 4
  24. 9
  25. 72
  26. 4
  27. 6
  28. 4
  29. 5
  30. 2
  31. 45
  32. 3
  33. 27
  34. 63
  35. 6
  36. 81
  37. 8
  38. 9
  39. 2
  40. 5

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