← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 642 · 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 88 and take away the sum of its digits. What do you get?
  2. 2.564? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.846? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.6?37 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.2?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?211 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?272 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.831? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.20?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.691? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?904 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.3?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.2?99 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.491? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.20?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.7?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?051 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.72?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.29?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?336 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.21? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 61 and take away the sum of its digits. What do you get?
  23. 23.?384 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.177? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?910 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 65 and take away the sum of its digits. What do you get?
  27. 27.?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.6?74 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.361? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 66 and take away the sum of its digits. What do you get?
  31. 31.Take 77 and take away the sum of its digits. What do you get?
  32. 32.Take 28 and take away the sum of its digits. What do you get?
  33. 33.Take 99 and take away the sum of its digits. What do you get?
  34. 34.?493 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 53 and take away the sum of its digits. What do you get?
  36. 36.Take 19 and take away the sum of its digits. What do you get?
  37. 37.342? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.749? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.1?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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