← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 38 · 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 64 and take away the sum of its digits. What do you get?
  2. 2.9?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 55 and take away the sum of its digits. What do you get?
  4. 4.Take 81 and take away the sum of its digits. What do you get?
  5. 5.Take 57 and take away the sum of its digits. What do you get?
  6. 6.20?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.896? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.15? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 73 and take away the sum of its digits. What do you get?
  10. 10.238? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?290 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.7?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.5?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.28?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 28 and take away the sum of its digits. What do you get?
  17. 17.Take 99 and take away the sum of its digits. What do you get?
  18. 18.?312 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?27 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 54 and take away the sum of its digits. What do you get?
  21. 21.613? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?683 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?542 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.86?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?889 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.7?43 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 83 and take away the sum of its digits. What do you get?
  28. 28.?060 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?015 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.292? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.5?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 16 and take away the sum of its digits. What do you get?
  33. 33.7?59 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 45 and take away the sum of its digits. What do you get?
  35. 35.Take 60 and take away the sum of its digits. What do you get?
  36. 36.726? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 92 and take away the sum of its digits. What do you get?
  38. 38.104? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?547 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.4?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 54
  2. 1
  3. 45
  4. 72
  5. 45
  6. 8
  7. 4
  8. 3
  9. 63
  10. 5
  11. 7
  12. 5
  13. 2
  14. 7
  15. 1
  16. 18
  17. 81
  18. 3
  19. 9
  20. 45
  21. 8
  22. 1
  23. 7
  24. 7
  25. 2
  26. 4
  27. 72
  28. 3
  29. 3
  30. 5
  31. 4
  32. 9
  33. 6
  34. 36
  35. 54
  36. 3
  37. 81
  38. 4
  39. 2
  40. 2

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