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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 290 · 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. 1.41?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 64 and take away the sum of its digits. What do you get?
  3. 3.25?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?904 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.820? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 18 and take away the sum of its digits. What do you get?
  7. 7.Take 21 and take away the sum of its digits. What do you get?
  8. 8.1?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.1?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?827 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?188 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 83 and take away the sum of its digits. What do you get?
  14. 14.57?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 14 and take away the sum of its digits. What do you get?
  16. 16.Take 59 and take away the sum of its digits. What do you get?
  17. 17.Take 58 and take away the sum of its digits. What do you get?
  18. 18.?34 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 89 and take away the sum of its digits. What do you get?
  20. 20.59?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 51 and take away the sum of its digits. What do you get?
  22. 22.Take 70 and take away the sum of its digits. What do you get?
  23. 23.?251 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.250? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.2?60 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.2?46 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 84 and take away the sum of its digits. What do you get?
  28. 28.?319 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.4?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?057 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.564? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?493 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?149 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.799? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.331? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 30 and take away the sum of its digits. What do you get?
  37. 37.3?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 38 and take away the sum of its digits. What do you get?
  39. 39.Take 93 and take away the sum of its digits. What do you get?
  40. 40.1?02 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. 54
  3. 5
  4. 5
  5. 8
  6. 9
  7. 18
  8. 5
  9. 8
  10. 2
  11. 1
  12. 1
  13. 72
  14. 9
  15. 9
  16. 45
  17. 45
  18. 2
  19. 72
  20. 9
  21. 45
  22. 63
  23. 1
  24. 2
  25. 1
  26. 6
  27. 72
  28. 5
  29. 7
  30. 6
  31. 3
  32. 2
  33. 4
  34. 2
  35. 2
  36. 27
  37. 3
  38. 27
  39. 81
  40. 6

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