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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 244 · 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. 1.878? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.166? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 59 and take away the sum of its digits. What do you get?
  4. 4.Take 42 and take away the sum of its digits. What do you get?
  5. 5.Take 65 and take away the sum of its digits. What do you get?
  6. 6.Take 52 and take away the sum of its digits. What do you get?
  7. 7.26?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 20 and take away the sum of its digits. What do you get?
  9. 9.?894 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?872 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.8?10 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.5?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.72?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.87? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 94 and take away the sum of its digits. What do you get?
  16. 16.?415 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 53 and take away the sum of its digits. What do you get?
  18. 18.Take 96 and take away the sum of its digits. What do you get?
  19. 19.Take 83 and take away the sum of its digits. What do you get?
  20. 20.Take 85 and take away the sum of its digits. What do you get?
  21. 21.602? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?073 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.52?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.6?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 75 and take away the sum of its digits. What do you get?
  26. 26.5?44 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 68 and take away the sum of its digits. What do you get?
  28. 28.5?61 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 79 and take away the sum of its digits. What do you get?
  30. 30.8?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?271 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 99 and take away the sum of its digits. What do you get?
  33. 33.Take 78 and take away the sum of its digits. What do you get?
  34. 34.4?10 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.137? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.2?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.6?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 28 and take away the sum of its digits. What do you get?
  39. 39.Take 26 and take away the sum of its digits. What do you get?
  40. 40.?10 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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