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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 68 · 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.Take 19 and take away the sum of its digits. What do you get?
  2. 2.Take 82 and take away the sum of its digits. What do you get?
  3. 3.22?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 55 and take away the sum of its digits. What do you get?
  5. 5.266? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.1?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.1?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.284? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.30?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 18 and take away the sum of its digits. What do you get?
  11. 11.Take 31 and take away the sum of its digits. What do you get?
  12. 12.Take 36 and take away the sum of its digits. What do you get?
  13. 13.Take 93 and take away the sum of its digits. What do you get?
  14. 14.Take 25 and take away the sum of its digits. What do you get?
  15. 15.312? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.193? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.6?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 78 and take away the sum of its digits. What do you get?
  19. 19.Take 80 and take away the sum of its digits. What do you get?
  20. 20.?836 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?789 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?293 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.2?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?496 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.82?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?992 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.19?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?537 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.4?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?605 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.523? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.86?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 42 and take away the sum of its digits. What do you get?
  34. 34.4?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.3?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.360? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.48?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.5?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 63 and take away the sum of its digits. What do you get?
  40. 40.?242 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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