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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 970 · 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. 1.58?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 14 and take away the sum of its digits. What do you get?
  3. 3.Take 58 and take away the sum of its digits. What do you get?
  4. 4.Take 95 and take away the sum of its digits. What do you get?
  5. 5.588? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.256? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 82 and take away the sum of its digits. What do you get?
  8. 8.630? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.33?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 30 and take away the sum of its digits. What do you get?
  11. 11.48?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 64 and take away the sum of its digits. What do you get?
  13. 13.Take 63 and take away the sum of its digits. What do you get?
  14. 14.395? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.76?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 52 and take away the sum of its digits. What do you get?
  17. 17.Take 18 and take away the sum of its digits. What do you get?
  18. 18.194? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 80 and take away the sum of its digits. What do you get?
  20. 20.22?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 22 and take away the sum of its digits. What do you get?
  22. 22.Take 54 and take away the sum of its digits. What do you get?
  23. 23.Take 89 and take away the sum of its digits. What do you get?
  24. 24.59?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 55 and take away the sum of its digits. What do you get?
  26. 26.3?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.643? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 44 and take away the sum of its digits. What do you get?
  29. 29.?552 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 51 and take away the sum of its digits. What do you get?
  31. 31.347? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.81?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 29 and take away the sum of its digits. What do you get?
  34. 34.72?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.58?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.44? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.2?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?340 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?890 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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