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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 301 · 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.?329 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?053 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 62 and take away the sum of its digits. What do you get?
  4. 4.1?92 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 22 and take away the sum of its digits. What do you get?
  6. 6.?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.514? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 94 and take away the sum of its digits. What do you get?
  9. 9.?322 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 26 and take away the sum of its digits. What do you get?
  11. 11.Take 84 and take away the sum of its digits. What do you get?
  12. 12.Take 53 and take away the sum of its digits. What do you get?
  13. 13.8?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.23?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?633 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 29 and take away the sum of its digits. What do you get?
  17. 17.Take 97 and take away the sum of its digits. What do you get?
  18. 18.Take 47 and take away the sum of its digits. What do you get?
  19. 19.?784 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?002 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?500 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?390 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.88?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.7?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.849? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 31 and take away the sum of its digits. What do you get?
  27. 27.Take 30 and take away the sum of its digits. What do you get?
  28. 28.Take 39 and take away the sum of its digits. What do you get?
  29. 29.4?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.4?76 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?920 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.589? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?411 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.4?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.217? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?004 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 17 and take away the sum of its digits. What do you get?
  38. 38.13?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.485? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?552 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. 1
  3. 54
  4. 6
  5. 18
  6. 7
  7. 8
  8. 81
  9. 2
  10. 18
  11. 72
  12. 45
  13. 2
  14. 4
  15. 6
  16. 18
  17. 81
  18. 36
  19. 8
  20. 7
  21. 4
  22. 6
  23. 4
  24. 8
  25. 6
  26. 27
  27. 27
  28. 27
  29. 2
  30. 1
  31. 7
  32. 5
  33. 3
  34. 5
  35. 8
  36. 5
  37. 9
  38. 7
  39. 1
  40. 6

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