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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 437 · 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. 1.57?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 40 and take away the sum of its digits. What do you get?
  3. 3.57?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.20?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.3?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 98 and take away the sum of its digits. What do you get?
  7. 7.Take 55 and take away the sum of its digits. What do you get?
  8. 8.23?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.692? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.34?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 77 and take away the sum of its digits. What do you get?
  13. 13.Take 11 and take away the sum of its digits. What do you get?
  14. 14.48?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.538? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.414? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?091 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.1?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.574? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.2?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 36 and take away the sum of its digits. What do you get?
  22. 22.2?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.131? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 17 and take away the sum of its digits. What do you get?
  25. 25.Take 78 and take away the sum of its digits. What do you get?
  26. 26.168? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?943 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.5?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.332? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.20?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 66 and take away the sum of its digits. What do you get?
  32. 32.Take 60 and take away the sum of its digits. What do you get?
  33. 33.?919 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.?421 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 32 and take away the sum of its digits. What do you get?
  36. 36.226? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 96 and take away the sum of its digits. What do you get?
  38. 38.Take 28 and take away the sum of its digits. What do you get?
  39. 39.453? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 24 and take away the sum of its digits. What do you get?

Answer key

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

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