← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 945 · 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. 1.98? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.6?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?317 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?653 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.2?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?444 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?655 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.22?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 81 and take away the sum of its digits. What do you get?
  10. 10.Take 53 and take away the sum of its digits. What do you get?
  11. 11.?026 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?631 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?427 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 73 and take away the sum of its digits. What do you get?
  15. 15.883? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.1?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 74 and take away the sum of its digits. What do you get?
  18. 18.5?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.82?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 47 and take away the sum of its digits. What do you get?
  21. 21.3?39 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.1?23 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 63 and take away the sum of its digits. What do you get?
  24. 24.?299 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.57?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?201 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 79 and take away the sum of its digits. What do you get?
  28. 28.Take 94 and take away the sum of its digits. What do you get?
  29. 29.?077 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.80?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?445 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.454? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.72?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 96 and take away the sum of its digits. What do you get?
  35. 35.49?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.65? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.1?08 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?872 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.79?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.3?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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