← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 17 · 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. 1.25?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?46 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.69?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.13?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 22 and take away the sum of its digits. What do you get?
  6. 6.12?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.6?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 20 and take away the sum of its digits. What do you get?
  10. 10.147? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.46?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 94 and take away the sum of its digits. What do you get?
  13. 13.?206 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?807 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 33 and take away the sum of its digits. What do you get?
  16. 16.?678 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.751? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?700 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 78 and take away the sum of its digits. What do you get?
  20. 20.113? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?667 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.739? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.5?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?093 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.1?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?158 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?520 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 35 and take away the sum of its digits. What do you get?
  29. 29.Take 32 and take away the sum of its digits. What do you get?
  30. 30.814? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.3?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.67?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.1?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 40 and take away the sum of its digits. What do you get?
  36. 36.1?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.104? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.15?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?470 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.380? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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