← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 334 · 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 59 and take away the sum of its digits. What do you get?
  2. 2.Take 47 and take away the sum of its digits. What do you get?
  3. 3.8?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.274? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.54?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 11 and take away the sum of its digits. What do you get?
  7. 7.Take 87 and take away the sum of its digits. What do you get?
  8. 8.42?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.88?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.440? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.291? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 45 and take away the sum of its digits. What do you get?
  13. 13.?215 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?233 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?845 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?739 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.1?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 23 and take away the sum of its digits. What do you get?
  19. 19.308? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?547 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 91 and take away the sum of its digits. What do you get?
  22. 22.?343 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 40 and take away the sum of its digits. What do you get?
  24. 24.45?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.581? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 96 and take away the sum of its digits. What do you get?
  27. 27.Take 31 and take away the sum of its digits. What do you get?
  28. 28.86?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.27?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?707 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.462? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 86 and take away the sum of its digits. What do you get?
  33. 33.8?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.8?40 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 26 and take away the sum of its digits. What do you get?
  36. 36.?123 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.7?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.21? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.5?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.772? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

Free maths tricks lessons, practice and worksheets at talentjr.in/maths-tricks