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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 547 · 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 33 and take away the sum of its digits. What do you get?
  2. 2.Take 22 and take away the sum of its digits. What do you get?
  3. 3.?27 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?735 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.168? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 38 and take away the sum of its digits. What do you get?
  7. 7.?880 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 58 and take away the sum of its digits. What do you get?
  9. 9.?028 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.2?44 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 18 and take away the sum of its digits. What do you get?
  12. 12.7?97 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?797 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.152? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.4?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?104 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 48 and take away the sum of its digits. What do you get?
  18. 18.79?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.25?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 16 and take away the sum of its digits. What do you get?
  21. 21.Take 19 and take away the sum of its digits. What do you get?
  22. 22.?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 59 and take away the sum of its digits. What do you get?
  24. 24.Take 96 and take away the sum of its digits. What do you get?
  25. 25.16? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?314 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.197? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.80? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.4?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.2?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 66 and take away the sum of its digits. What do you get?
  33. 33.722? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.36?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.5?32 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.510? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?670 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.3?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 44 and take away the sum of its digits. What do you get?
  40. 40.Take 14 and take away the sum of its digits. What do you get?

Answer key

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

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