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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 717 · 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.?651 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?622 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.526? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.5?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.34?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.12?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?813 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 35 and take away the sum of its digits. What do you get?
  9. 9.Take 63 and take away the sum of its digits. What do you get?
  10. 10.Take 91 and take away the sum of its digits. What do you get?
  11. 11.3?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.12?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.649? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.365? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 82 and take away the sum of its digits. What do you get?
  16. 16.293? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 84 and take away the sum of its digits. What do you get?
  18. 18.25?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?224 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.6?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.5?61 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.5?60 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 93 and take away the sum of its digits. What do you get?
  24. 24.Take 11 and take away the sum of its digits. What do you get?
  25. 25.Take 37 and take away the sum of its digits. What do you get?
  26. 26.6?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 20 and take away the sum of its digits. What do you get?
  28. 28.Take 60 and take away the sum of its digits. What do you get?
  29. 29.Take 99 and take away the sum of its digits. What do you get?
  30. 30.?800 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.20?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.7?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.6?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.380? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 14 and take away the sum of its digits. What do you get?
  37. 37.?821 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 21 and take away the sum of its digits. What do you get?
  39. 39.Take 30 and take away the sum of its digits. What do you get?
  40. 40.44?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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