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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 941 · 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 26 and take away the sum of its digits. What do you get?
  2. 2.1?94 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.887? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?098 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?158 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.80?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.25?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.8?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.1?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.60?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.488? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 97 and take away the sum of its digits. What do you get?
  13. 13.Take 44 and take away the sum of its digits. What do you get?
  14. 14.Take 51 and take away the sum of its digits. What do you get?
  15. 15.Take 58 and take away the sum of its digits. What do you get?
  16. 16.Take 33 and take away the sum of its digits. What do you get?
  17. 17.47?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.32?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.61? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?570 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?015 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.6?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 88 and take away the sum of its digits. What do you get?
  24. 24.Take 65 and take away the sum of its digits. What do you get?
  25. 25.?782 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 24 and take away the sum of its digits. What do you get?
  27. 27.351? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?157 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.3?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 63 and take away the sum of its digits. What do you get?
  31. 31.?934 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?767 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 25 and take away the sum of its digits. What do you get?
  34. 34.34?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?939 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?101 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 80 and take away the sum of its digits. What do you get?
  38. 38.Take 49 and take away the sum of its digits. What do you get?
  39. 39.?287 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.8?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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