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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 162 · 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.Take 41 and take away the sum of its digits. What do you get?
  2. 2.?845 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.5?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?490 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 72 and take away the sum of its digits. What do you get?
  6. 6.7?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?262 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.29?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 68 and take away the sum of its digits. What do you get?
  10. 10.7?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.3?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.489? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 52 and take away the sum of its digits. What do you get?
  15. 15.77?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 17 and take away the sum of its digits. What do you get?
  17. 17.2?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 47 and take away the sum of its digits. What do you get?
  19. 19.260? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 63 and take away the sum of its digits. What do you get?
  21. 21.Take 85 and take away the sum of its digits. What do you get?
  22. 22.Take 93 and take away the sum of its digits. What do you get?
  23. 23.9?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 12 and take away the sum of its digits. What do you get?
  25. 25.713? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?510 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 97 and take away the sum of its digits. What do you get?
  28. 28.10?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 26 and take away the sum of its digits. What do you get?
  30. 30.?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.461? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.1?84 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.80?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.61?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 74 and take away the sum of its digits. What do you get?
  36. 36.57?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 39 and take away the sum of its digits. What do you get?
  38. 38.Take 75 and take away the sum of its digits. What do you get?
  39. 39.5?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.28?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 36
  2. 1
  3. 7
  4. 5
  5. 63
  6. 3
  7. 8
  8. 4
  9. 54
  10. 2
  11. 3
  12. 7
  13. 6
  14. 45
  15. 1
  16. 9
  17. 2
  18. 36
  19. 1
  20. 54
  21. 72
  22. 81
  23. 9
  24. 9
  25. 7
  26. 3
  27. 81
  28. 5
  29. 18
  30. 8
  31. 7
  32. 5
  33. 1
  34. 3
  35. 63
  36. 1
  37. 27
  38. 63
  39. 4
  40. 9

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