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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 966 · 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.?890 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?40 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 19 and take away the sum of its digits. What do you get?
  4. 4.?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 68 and take away the sum of its digits. What do you get?
  6. 6.1?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 50 and take away the sum of its digits. What do you get?
  8. 8.Take 76 and take away the sum of its digits. What do you get?
  9. 9.?808 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.7?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.5?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 51 and take away the sum of its digits. What do you get?
  14. 14.4?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 66 and take away the sum of its digits. What do you get?
  16. 16.?188 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 84 and take away the sum of its digits. What do you get?
  18. 18.?130 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?215 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.885? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 93 and take away the sum of its digits. What do you get?
  22. 22.71?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.541? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.15?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 58 and take away the sum of its digits. What do you get?
  26. 26.?710 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.26?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 57 and take away the sum of its digits. What do you get?
  29. 29.?989 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 81 and take away the sum of its digits. What do you get?
  31. 31.Take 87 and take away the sum of its digits. What do you get?
  32. 32.6?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.6?33 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.67?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.490? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 94 and take away the sum of its digits. What do you get?
  37. 37.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 38 and take away the sum of its digits. What do you get?
  39. 39.Take 45 and take away the sum of its digits. What do you get?
  40. 40.47? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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