← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 987 · 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 79 and take away the sum of its digits. What do you get?
  2. 2.516? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.2?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 49 and take away the sum of its digits. What do you get?
  5. 5.Take 24 and take away the sum of its digits. What do you get?
  6. 6.Take 68 and take away the sum of its digits. What do you get?
  7. 7.?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.760? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.52?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?500 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?857 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 90 and take away the sum of its digits. What do you get?
  13. 13.?688 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.3?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.1?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.13?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 26 and take away the sum of its digits. What do you get?
  18. 18.459? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?097 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?822 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?175 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?058 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?035 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.56?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 19 and take away the sum of its digits. What do you get?
  26. 26.?238 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.44?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.4?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.437? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 32 and take away the sum of its digits. What do you get?
  31. 31.Take 50 and take away the sum of its digits. What do you get?
  32. 32.Take 31 and take away the sum of its digits. What do you get?
  33. 33.20?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.72?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 18 and take away the sum of its digits. What do you get?
  36. 36.39?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 30 and take away the sum of its digits. What do you get?
  38. 38.?134 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.668? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?492 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 63
  2. 6
  3. 6
  4. 36
  5. 18
  6. 54
  7. 8
  8. 5
  9. 9
  10. 4
  11. 7
  12. 81
  13. 5
  14. 9
  15. 9
  16. 4
  17. 18
  18. 9
  19. 2
  20. 6
  21. 5
  22. 5
  23. 1
  24. 4
  25. 9
  26. 5
  27. 4
  28. 4
  29. 4
  30. 27
  31. 45
  32. 27
  33. 1
  34. 3
  35. 9
  36. 4
  37. 27
  38. 1
  39. 7
  40. 3

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