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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 931 · 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. 1.7?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.44?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 41 and take away the sum of its digits. What do you get?
  4. 4.152? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 28 and take away the sum of its digits. What do you get?
  6. 6.554? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.9?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?997 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.17?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 93 and take away the sum of its digits. What do you get?
  11. 11.Take 20 and take away the sum of its digits. What do you get?
  12. 12.?688 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.77?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 31 and take away the sum of its digits. What do you get?
  15. 15.?511 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 44 and take away the sum of its digits. What do you get?
  17. 17.57?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?665 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?397 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?510 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.51?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.273? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.16?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?564 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.2?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 11 and take away the sum of its digits. What do you get?
  27. 27.8?94 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?056 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.38?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?637 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 16 and take away the sum of its digits. What do you get?
  32. 32.1?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.5?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.397? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?497 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 50 and take away the sum of its digits. What do you get?
  37. 37.?159 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.1?58 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 36 and take away the sum of its digits. What do you get?
  40. 40.30?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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