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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 640 · 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. 1.6?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.220? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.1?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 86 and take away the sum of its digits. What do you get?
  5. 5.?068 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 78 and take away the sum of its digits. What do you get?
  7. 7.16?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 23 and take away the sum of its digits. What do you get?
  9. 9.?187 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?314 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 25 and take away the sum of its digits. What do you get?
  13. 13.56? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 89 and take away the sum of its digits. What do you get?
  15. 15.Take 83 and take away the sum of its digits. What do you get?
  16. 16.Take 46 and take away the sum of its digits. What do you get?
  17. 17.19?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 14 and take away the sum of its digits. What do you get?
  19. 19.120? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 63 and take away the sum of its digits. What do you get?
  21. 21.3?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.1?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 77 and take away the sum of its digits. What do you get?
  24. 24.56?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.66?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?556 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 11 and take away the sum of its digits. What do you get?
  28. 28.44?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 32 and take away the sum of its digits. What do you get?
  30. 30.Take 49 and take away the sum of its digits. What do you get?
  31. 31.?91 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?276 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 73 and take away the sum of its digits. What do you get?
  34. 34.72?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 52 and take away the sum of its digits. What do you get?
  36. 36.8?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?073 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?213 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 40 and take away the sum of its digits. What do you get?

Answer key

  1. 5
  2. 5
  3. 6
  4. 72
  5. 4
  6. 63
  7. 2
  8. 18
  9. 2
  10. 4
  11. 1
  12. 18
  13. 7
  14. 72
  15. 72
  16. 36
  17. 5
  18. 9
  19. 6
  20. 54
  21. 9
  22. 8
  23. 63
  24. 6
  25. 5
  26. 2
  27. 9
  28. 7
  29. 27
  30. 36
  31. 8
  32. 3
  33. 63
  34. 4
  35. 45
  36. 8
  37. 8
  38. 3
  39. 1
  40. 36

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