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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 575 · 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. 1.601? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.1?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 28 and take away the sum of its digits. What do you get?
  4. 4.?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.112? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.140? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 11 and take away the sum of its digits. What do you get?
  8. 8.767? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 83 and take away the sum of its digits. What do you get?
  10. 10.?184 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.49?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?708 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.4?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.1?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 59 and take away the sum of its digits. What do you get?
  16. 16.Take 99 and take away the sum of its digits. What do you get?
  17. 17.Take 22 and take away the sum of its digits. What do you get?
  18. 18.23?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.48?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 53 and take away the sum of its digits. What do you get?
  21. 21.?781 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.712? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 31 and take away the sum of its digits. What do you get?
  24. 24.?286 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?060 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.35?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.68?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.1?54 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?637 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 34 and take away the sum of its digits. What do you get?
  31. 31.473? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?436 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.1?84 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.40?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.75?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?012 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.6?66 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.3?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.550? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.470? 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. 8
  3. 18
  4. 4
  5. 5
  6. 4
  7. 9
  8. 7
  9. 72
  10. 5
  11. 8
  12. 3
  13. 5
  14. 6
  15. 45
  16. 81
  17. 18
  18. 7
  19. 1
  20. 45
  21. 2
  22. 8
  23. 27
  24. 2
  25. 3
  26. 8
  27. 6
  28. 8
  29. 2
  30. 27
  31. 4
  32. 5
  33. 5
  34. 7
  35. 1
  36. 6
  37. 9
  38. 3
  39. 8
  40. 7

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