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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 849 · 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 11 and take away the sum of its digits. What do you get?
  2. 2.19?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?426 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 58 and take away the sum of its digits. What do you get?
  5. 5.Take 89 and take away the sum of its digits. What do you get?
  6. 6.7?35 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 51 and take away the sum of its digits. What do you get?
  8. 8.Take 95 and take away the sum of its digits. What do you get?
  9. 9.62?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 27 and take away the sum of its digits. What do you get?
  11. 11.Take 63 and take away the sum of its digits. What do you get?
  12. 12.Take 47 and take away the sum of its digits. What do you get?
  13. 13.203? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 53 and take away the sum of its digits. What do you get?
  15. 15.453? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?979 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 75 and take away the sum of its digits. What do you get?
  18. 18.?196 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?605 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.7?31 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.492? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?535 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.14?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?059 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.41?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.8?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.1?10 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.87?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 16 and take away the sum of its digits. What do you get?
  30. 30.?347 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 85 and take away the sum of its digits. What do you get?
  32. 32.?674 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.59? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.180? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 61 and take away the sum of its digits. What do you get?
  36. 36.Take 49 and take away the sum of its digits. What do you get?
  37. 37.9?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 21 and take away the sum of its digits. What do you get?
  39. 39.Take 33 and take away the sum of its digits. What do you get?
  40. 40.4?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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