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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 729 · 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.?813 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 47 and take away the sum of its digits. What do you get?
  3. 3.15?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?506 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?437 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.24?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?152 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 16 and take away the sum of its digits. What do you get?
  10. 10.3?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.1?46 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.18? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.68? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 59 and take away the sum of its digits. What do you get?
  16. 16.7?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.214? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?913 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 54 and take away the sum of its digits. What do you get?
  20. 20.?808 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.300? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 63 and take away the sum of its digits. What do you get?
  23. 23.87?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?318 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 23 and take away the sum of its digits. What do you get?
  26. 26.?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?426 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.49? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 38 and take away the sum of its digits. What do you get?
  30. 30.?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 12 and take away the sum of its digits. What do you get?
  32. 32.Take 65 and take away the sum of its digits. What do you get?
  33. 33.?111 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 18 and take away the sum of its digits. What do you get?
  35. 35.873? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 58 and take away the sum of its digits. What do you get?
  37. 37.?435 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.8?60 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.54?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.184? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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