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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 623 · 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.?941 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 78 and take away the sum of its digits. What do you get?
  3. 3.Take 14 and take away the sum of its digits. What do you get?
  4. 4.240? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 37 and take away the sum of its digits. What do you get?
  6. 6.?543 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 19 and take away the sum of its digits. What do you get?
  8. 8.26? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?514 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.8?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 34 and take away the sum of its digits. What do you get?
  13. 13.?101 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.842? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 76 and take away the sum of its digits. What do you get?
  16. 16.?470 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 71 and take away the sum of its digits. What do you get?
  18. 18.?58 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.18?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?685 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.5?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 41 and take away the sum of its digits. What do you get?
  24. 24.890? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 45 and take away the sum of its digits. What do you get?
  26. 26.8?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 57 and take away the sum of its digits. What do you get?
  28. 28.3?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.71?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 25 and take away the sum of its digits. What do you get?
  31. 31.?277 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 55 and take away the sum of its digits. What do you get?
  33. 33.35?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 54 and take away the sum of its digits. What do you get?
  35. 35.42?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.4?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 48 and take away the sum of its digits. What do you get?
  38. 38.4?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.42?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?99 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. 63
  3. 9
  4. 3
  5. 27
  6. 6
  7. 9
  8. 1
  9. 8
  10. 2
  11. 2
  12. 27
  13. 7
  14. 4
  15. 63
  16. 7
  17. 63
  18. 5
  19. 9
  20. 8
  21. 2
  22. 6
  23. 36
  24. 1
  25. 36
  26. 7
  27. 45
  28. 8
  29. 6
  30. 18
  31. 2
  32. 45
  33. 1
  34. 45
  35. 7
  36. 5
  37. 36
  38. 5
  39. 1
  40. 9

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