← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 374 · 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 30 and take away the sum of its digits. What do you get?
  2. 2.13?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 81 and take away the sum of its digits. What do you get?
  4. 4.?668 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?239 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?53 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?759 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 41 and take away the sum of its digits. What do you get?
  9. 9.108? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.2?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.1?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 96 and take away the sum of its digits. What do you get?
  13. 13.Take 61 and take away the sum of its digits. What do you get?
  14. 14.549? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.22?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.44? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?807 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.80?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.30?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.29?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?352 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.2?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?910 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.22?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 11 and take away the sum of its digits. What do you get?
  26. 26.?124 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 46 and take away the sum of its digits. What do you get?
  28. 28.?479 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.529? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.4?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.70? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.35?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 65 and take away the sum of its digits. What do you get?
  34. 34.6?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 63 and take away the sum of its digits. What do you get?
  36. 36.Take 98 and take away the sum of its digits. What do you get?
  37. 37.?874 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.3?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.5?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 25 and take away the sum of its digits. What do you get?

Answer key

  1. 27
  2. 1
  3. 72
  4. 7
  5. 4
  6. 1
  7. 6
  8. 36
  9. 9
  10. 7
  11. 9
  12. 81
  13. 54
  14. 9
  15. 4
  16. 1
  17. 3
  18. 3
  19. 6
  20. 4
  21. 8
  22. 7
  23. 8
  24. 5
  25. 9
  26. 2
  27. 36
  28. 7
  29. 2
  30. 2
  31. 2
  32. 6
  33. 54
  34. 9
  35. 54
  36. 81
  37. 8
  38. 7
  39. 6
  40. 18

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