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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 459 · 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. 1.2?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 88 and take away the sum of its digits. What do you get?
  3. 3.633? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 74 and take away the sum of its digits. What do you get?
  5. 5.708? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.46? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 23 and take away the sum of its digits. What do you get?
  8. 8.Take 13 and take away the sum of its digits. What do you get?
  9. 9.?123 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 51 and take away the sum of its digits. What do you get?
  11. 11.70?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.78?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.380? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 93 and take away the sum of its digits. What do you get?
  16. 16.6?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.8?54 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.790? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 30 and take away the sum of its digits. What do you get?
  20. 20.7?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.1?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.85?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 96 and take away the sum of its digits. What do you get?
  24. 24.48?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.11?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?957 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.65?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 52 and take away the sum of its digits. What do you get?
  29. 29.8?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.3?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 86 and take away the sum of its digits. What do you get?
  32. 32.?895 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 24 and take away the sum of its digits. What do you get?
  34. 34.9?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.4?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 35 and take away the sum of its digits. What do you get?
  37. 37.Take 99 and take away the sum of its digits. What do you get?
  38. 38.?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 20 and take away the sum of its digits. What do you get?
  40. 40.44?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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