← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 587 · 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.?255 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?158 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 32 and take away the sum of its digits. What do you get?
  4. 4.82?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 49 and take away the sum of its digits. What do you get?
  6. 6.Take 70 and take away the sum of its digits. What do you get?
  7. 7.Take 29 and take away the sum of its digits. What do you get?
  8. 8.596? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.7?51 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.70?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?789 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?556 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 99 and take away the sum of its digits. What do you get?
  14. 14.428? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?77 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?155 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 11 and take away the sum of its digits. What do you get?
  18. 18.?362 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.7?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?941 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?681 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?772 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.572? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 94 and take away the sum of its digits. What do you get?
  25. 25.171? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 95 and take away the sum of its digits. What do you get?
  27. 27.73?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 31 and take away the sum of its digits. What do you get?
  29. 29.Take 16 and take away the sum of its digits. What do you get?
  30. 30.23? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.204? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 76 and take away the sum of its digits. What do you get?
  33. 33.?307 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.4?10 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.1?47 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?042 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.87?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.84?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.741? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.1?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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