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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 888 · 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. 1.6?51 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?078 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.392? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 31 and take away the sum of its digits. What do you get?
  5. 5.?055 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.86?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?483 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.24?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.8?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 32 and take away the sum of its digits. What do you get?
  11. 11.2?67 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?908 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 42 and take away the sum of its digits. What do you get?
  14. 14.527? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 97 and take away the sum of its digits. What do you get?
  16. 16.68?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 95 and take away the sum of its digits. What do you get?
  18. 18.Take 56 and take away the sum of its digits. What do you get?
  19. 19.?600 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?426 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.38?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?97 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.2?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.7?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.185? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.83?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?187 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?067 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 12 and take away the sum of its digits. What do you get?
  30. 30.43?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.22?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?606 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.6?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.3?59 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.190? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 45 and take away the sum of its digits. What do you get?
  37. 37.Take 88 and take away the sum of its digits. What do you get?
  38. 38.Take 92 and take away the sum of its digits. What do you get?
  39. 39.5?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.6?35 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. 3
  3. 4
  4. 27
  5. 8
  6. 4
  7. 3
  8. 8
  9. 4
  10. 27
  11. 3
  12. 1
  13. 36
  14. 4
  15. 81
  16. 6
  17. 81
  18. 45
  19. 3
  20. 6
  21. 1
  22. 2
  23. 5
  24. 7
  25. 4
  26. 5
  27. 2
  28. 5
  29. 9
  30. 4
  31. 8
  32. 6
  33. 5
  34. 1
  35. 8
  36. 36
  37. 72
  38. 81
  39. 1
  40. 4

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