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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 490 · 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. 1.87?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.3?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 97 and take away the sum of its digits. What do you get?
  4. 4.?193 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 73 and take away the sum of its digits. What do you get?
  6. 6.?173 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.44?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.395? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.745? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 96 and take away the sum of its digits. What do you get?
  11. 11.Take 29 and take away the sum of its digits. What do you get?
  12. 12.?353 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 22 and take away the sum of its digits. What do you get?
  14. 14.Take 38 and take away the sum of its digits. What do you get?
  15. 15.Take 31 and take away the sum of its digits. What do you get?
  16. 16.Take 61 and take away the sum of its digits. What do you get?
  17. 17.82?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.42?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?871 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 48 and take away the sum of its digits. What do you get?
  21. 21.?204 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 58 and take away the sum of its digits. What do you get?
  23. 23.654? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.7?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 33 and take away the sum of its digits. What do you get?
  26. 26.?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.5?76 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?114 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.8?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 70 and take away the sum of its digits. What do you get?
  31. 31.Take 82 and take away the sum of its digits. What do you get?
  32. 32.9?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 53 and take away the sum of its digits. What do you get?
  34. 34.5?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?911 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.73?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 30 and take away the sum of its digits. What do you get?
  38. 38.?37 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.2?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.13? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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