← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 126 · 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. 1.63?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?664 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 14 and take away the sum of its digits. What do you get?
  4. 4.?874 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.62?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.289? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.56?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.89? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 97 and take away the sum of its digits. What do you get?
  10. 10.Take 18 and take away the sum of its digits. What do you get?
  11. 11.55? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.362? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.2?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 12 and take away the sum of its digits. What do you get?
  15. 15.1?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.73?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?340 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?021 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 52 and take away the sum of its digits. What do you get?
  20. 20.Take 43 and take away the sum of its digits. What do you get?
  21. 21.?312 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.82?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 89 and take away the sum of its digits. What do you get?
  24. 24.457? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?577 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?948 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.89?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.8?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.7?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.5?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.480? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 82 and take away the sum of its digits. What do you get?
  34. 34.?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 74 and take away the sum of its digits. What do you get?
  36. 36.3?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 57 and take away the sum of its digits. What do you get?
  38. 38.320? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.83?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.400? 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. 2
  3. 9
  4. 8
  5. 4
  6. 8
  7. 4
  8. 1
  9. 81
  10. 9
  11. 8
  12. 7
  13. 8
  14. 9
  15. 3
  16. 9
  17. 2
  18. 6
  19. 45
  20. 36
  21. 3
  22. 8
  23. 72
  24. 2
  25. 8
  26. 6
  27. 8
  28. 1
  29. 7
  30. 3
  31. 1
  32. 6
  33. 72
  34. 6
  35. 63
  36. 3
  37. 45
  38. 4
  39. 2
  40. 5

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