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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 791 · 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. 1.28?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.12?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.67?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.87?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.139? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.5?18 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.8?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 32 and take away the sum of its digits. What do you get?
  9. 9.65?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 38 and take away the sum of its digits. What do you get?
  11. 11.Take 70 and take away the sum of its digits. What do you get?
  12. 12.19?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 41 and take away the sum of its digits. What do you get?
  14. 14.?037 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.46? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.22?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?643 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.1?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.5?92 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 72 and take away the sum of its digits. What do you get?
  22. 22.3?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 94 and take away the sum of its digits. What do you get?
  24. 24.?593 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 29 and take away the sum of its digits. What do you get?
  26. 26.885? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.173? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.67? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.10?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 15 and take away the sum of its digits. What do you get?
  31. 31.Take 93 and take away the sum of its digits. What do you get?
  32. 32.2?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 23 and take away the sum of its digits. What do you get?
  34. 34.5?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.453? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 83 and take away the sum of its digits. What do you get?
  37. 37.?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 40 and take away the sum of its digits. What do you get?
  39. 39.?741 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.44?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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