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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 271 · 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. 1.367? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.213? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.337? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.18? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.8?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?139 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.27?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 86 and take away the sum of its digits. What do you get?
  10. 10.Take 70 and take away the sum of its digits. What do you get?
  11. 11.32?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 41 and take away the sum of its digits. What do you get?
  13. 13.?199 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.2?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 99 and take away the sum of its digits. What do you get?
  16. 16.Take 63 and take away the sum of its digits. What do you get?
  17. 17.Take 17 and take away the sum of its digits. What do you get?
  18. 18.5?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?374 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.1?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.516? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?809 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.1?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 47 and take away the sum of its digits. What do you get?
  26. 26.Take 28 and take away the sum of its digits. What do you get?
  27. 27.72?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.705? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?919 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?343 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.194? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.128? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 38 and take away the sum of its digits. What do you get?
  35. 35.?931 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.85?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.4?32 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?296 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?512 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.6?02 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. 5
  4. 9
  5. 5
  6. 1
  7. 5
  8. 1
  9. 72
  10. 63
  11. 1
  12. 36
  13. 8
  14. 1
  15. 81
  16. 54
  17. 9
  18. 5
  19. 4
  20. 5
  21. 6
  22. 1
  23. 8
  24. 1
  25. 36
  26. 18
  27. 8
  28. 6
  29. 8
  30. 2
  31. 8
  32. 4
  33. 7
  34. 27
  35. 5
  36. 5
  37. 9
  38. 1
  39. 1
  40. 1

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