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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 520 · 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. 1.569? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.128? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.7?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.3?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 42 and take away the sum of its digits. What do you get?
  6. 6.1?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.75? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 39 and take away the sum of its digits. What do you get?
  10. 10.5?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?233 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.174? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.7?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 73 and take away the sum of its digits. What do you get?
  15. 15.Take 94 and take away the sum of its digits. What do you get?
  16. 16.?692 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?579 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.7?74 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.13?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.300? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 36 and take away the sum of its digits. What do you get?
  22. 22.Take 77 and take away the sum of its digits. What do you get?
  23. 23.41?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.50?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 48 and take away the sum of its digits. What do you get?
  27. 27.7?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.51?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 69 and take away the sum of its digits. What do you get?
  30. 30.602? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?971 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 84 and take away the sum of its digits. What do you get?
  33. 33.Take 83 and take away the sum of its digits. What do you get?
  34. 34.Take 68 and take away the sum of its digits. What do you get?
  35. 35.Take 35 and take away the sum of its digits. What do you get?
  36. 36.247? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?070 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 26 and take away the sum of its digits. What do you get?
  39. 39.?964 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. 7
  2. 7
  3. 9
  4. 3
  5. 36
  6. 1
  7. 6
  8. 6
  9. 27
  10. 6
  11. 1
  12. 6
  13. 6
  14. 63
  15. 81
  16. 1
  17. 6
  18. 9
  19. 6
  20. 6
  21. 27
  22. 63
  23. 1
  24. 6
  25. 7
  26. 36
  27. 4
  28. 6
  29. 54
  30. 1
  31. 1
  32. 72
  33. 72
  34. 54
  35. 27
  36. 5
  37. 2
  38. 18
  39. 8
  40. 45

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