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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 516 · 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. 1.8?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 16 and take away the sum of its digits. What do you get?
  3. 3.Take 45 and take away the sum of its digits. What do you get?
  4. 4.?84 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.4?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 32 and take away the sum of its digits. What do you get?
  7. 7.893? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.18?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.22?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?035 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 89 and take away the sum of its digits. What do you get?
  12. 12.4?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.31?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 87 and take away the sum of its digits. What do you get?
  15. 15.?302 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 42 and take away the sum of its digits. What do you get?
  17. 17.Take 59 and take away the sum of its digits. What do you get?
  18. 18.83?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.2?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 50 and take away the sum of its digits. What do you get?
  22. 22.691? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.8?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 41 and take away the sum of its digits. What do you get?
  25. 25.?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 26 and take away the sum of its digits. What do you get?
  27. 27.Take 47 and take away the sum of its digits. What do you get?
  28. 28.50?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.895? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.4?45 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?863 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.32? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.8?37 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.41?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 55 and take away the sum of its digits. What do you get?
  37. 37.219? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.538? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?380 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.6?67 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. 9
  3. 36
  4. 6
  5. 9
  6. 27
  7. 7
  8. 6
  9. 9
  10. 1
  11. 72
  12. 8
  13. 5
  14. 72
  15. 4
  16. 36
  17. 45
  18. 8
  19. 1
  20. 2
  21. 45
  22. 2
  23. 3
  24. 36
  25. 1
  26. 18
  27. 36
  28. 4
  29. 5
  30. 5
  31. 1
  32. 4
  33. 9
  34. 7
  35. 6
  36. 45
  37. 6
  38. 2
  39. 7
  40. 8

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