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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 101 · 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. 1.1?14 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.2?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?921 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?708 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 74 and take away the sum of its digits. What do you get?
  6. 6.14?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 43 and take away the sum of its digits. What do you get?
  8. 8.12? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 20 and take away the sum of its digits. What do you get?
  10. 10.Take 42 and take away the sum of its digits. What do you get?
  11. 11.Take 48 and take away the sum of its digits. What do you get?
  12. 12.?46 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 99 and take away the sum of its digits. What do you get?
  15. 15.8?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.6?76 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?778 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.268? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.8?67 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?508 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.62?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.490? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?996 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.3?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 87 and take away the sum of its digits. What do you get?
  26. 26.64?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 89 and take away the sum of its digits. What do you get?
  28. 28.?490 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 65 and take away the sum of its digits. What do you get?
  31. 31.3?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.7?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?236 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.776? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?746 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.7?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.4?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?123 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.106? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 56 and take away the sum of its digits. What do you get?

Answer key

  1. 3
  2. 6
  3. 6
  4. 3
  5. 63
  6. 4
  7. 36
  8. 6
  9. 18
  10. 36
  11. 36
  12. 8
  13. 5
  14. 81
  15. 6
  16. 8
  17. 5
  18. 2
  19. 6
  20. 5
  21. 3
  22. 5
  23. 3
  24. 9
  25. 72
  26. 8
  27. 72
  28. 5
  29. 2
  30. 54
  31. 1
  32. 8
  33. 7
  34. 7
  35. 1
  36. 4
  37. 3
  38. 3
  39. 2
  40. 45

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