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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 873 · 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.?938 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?730 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.52?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 63 and take away the sum of its digits. What do you get?
  5. 5.68?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.5?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?389 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.130? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 14 and take away the sum of its digits. What do you get?
  10. 10.Take 79 and take away the sum of its digits. What do you get?
  11. 11.?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?269 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 64 and take away the sum of its digits. What do you get?
  14. 14.8?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.71?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.873? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 70 and take away the sum of its digits. What do you get?
  18. 18.Take 69 and take away the sum of its digits. What do you get?
  19. 19.2?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?021 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.513? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.7?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.52?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.6?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?084 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?53 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.8?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 12 and take away the sum of its digits. What do you get?
  29. 29.Take 13 and take away the sum of its digits. What do you get?
  30. 30.1?66 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?668 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?134 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?976 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 98 and take away the sum of its digits. What do you get?
  35. 35.752? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.6?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 50 and take away the sum of its digits. What do you get?
  38. 38.?058 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.1?23 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.2?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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