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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 589 · 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.?210 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?457 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 74 and take away the sum of its digits. What do you get?
  4. 4.1?49 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.2?53 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.22?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.889? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?231 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 66 and take away the sum of its digits. What do you get?
  10. 10.205? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 99 and take away the sum of its digits. What do you get?
  12. 12.Take 87 and take away the sum of its digits. What do you get?
  13. 13.50?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.3?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.37?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 91 and take away the sum of its digits. What do you get?
  17. 17.Take 84 and take away the sum of its digits. What do you get?
  18. 18.?613 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.7?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 37 and take away the sum of its digits. What do you get?
  21. 21.Take 71 and take away the sum of its digits. What do you get?
  22. 22.2?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.824? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.5?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.54?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 34 and take away the sum of its digits. What do you get?
  27. 27.?281 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 18 and take away the sum of its digits. What do you get?
  29. 29.8?22 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 97 and take away the sum of its digits. What do you get?
  31. 31.?300 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.20?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.27?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.?420 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 12 and take away the sum of its digits. What do you get?
  36. 36.?122 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 47 and take away the sum of its digits. What do you get?
  39. 39.Take 95 and take away the sum of its digits. What do you get?
  40. 40.Take 69 and take away the sum of its digits. What do you get?

Answer key

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

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