← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 982 · 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 94 and take away the sum of its digits. What do you get?
  2. 2.Take 90 and take away the sum of its digits. What do you get?
  3. 3.?499 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 25 and take away the sum of its digits. What do you get?
  5. 5.322? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?134 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 69 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.?026 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 97 and take away the sum of its digits. What do you get?
  12. 12.307? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.56?1 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.Take 37 and take away the sum of its digits. What do you get?
  16. 16.Take 52 and take away the sum of its digits. What do you get?
  17. 17.3?67 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?033 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.2?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.59? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.77? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.1?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 38 and take away the sum of its digits. What do you get?
  25. 25.Take 32 and take away the sum of its digits. What do you get?
  26. 26.2?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.451? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.7?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?224 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 96 and take away the sum of its digits. What do you get?
  31. 31.53?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.443? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 62 and take away the sum of its digits. What do you get?
  34. 34.29?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.397? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.34?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?766 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 40 and take away the sum of its digits. What do you get?
  39. 39.3?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.22?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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