← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 178 · 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 26 and take away the sum of its digits. What do you get?
  2. 2.Take 75 and take away the sum of its digits. What do you get?
  3. 3.44?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.4?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 41 and take away the sum of its digits. What do you get?
  6. 6.?092 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 12 and take away the sum of its digits. What do you get?
  8. 8.Take 46 and take away the sum of its digits. What do you get?
  9. 9.Take 55 and take away the sum of its digits. What do you get?
  10. 10.?007 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.8?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.4?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.319? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?53 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 19 and take away the sum of its digits. What do you get?
  16. 16.7?44 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 50 and take away the sum of its digits. What do you get?
  18. 18.6?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 95 and take away the sum of its digits. What do you get?
  20. 20.3?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.73?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?811 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.12?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?597 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?148 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.48?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.49?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.21?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.10?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.22?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.7?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.3?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 78 and take away the sum of its digits. What do you get?
  35. 35.?377 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.6?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.64?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?043 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?879 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?634 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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