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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 916 · 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. 1.4?66 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.8?34 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 71 and take away the sum of its digits. What do you get?
  4. 4.67?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 11 and take away the sum of its digits. What do you get?
  6. 6.?916 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.52?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.13?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 34 and take away the sum of its digits. What do you get?
  10. 10.79?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.3?22 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?898 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.630? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 30 and take away the sum of its digits. What do you get?
  16. 16.Take 21 and take away the sum of its digits. What do you get?
  17. 17.Take 61 and take away the sum of its digits. What do you get?
  18. 18.1?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 59 and take away the sum of its digits. What do you get?
  20. 20.490? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.84?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.55?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 52 and take away the sum of its digits. What do you get?
  24. 24.2?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?003 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.85?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?161 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?160 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?902 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?403 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.608? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.614? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.845? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 62 and take away the sum of its digits. What do you get?
  35. 35.Take 40 and take away the sum of its digits. What do you get?
  36. 36.?699 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 39 and take away the sum of its digits. What do you get?
  38. 38.Take 56 and take away the sum of its digits. What do you get?
  39. 39.70? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.567? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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