← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 284 · 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.?933 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.308? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.20?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 22 and take away the sum of its digits. What do you get?
  5. 5.?691 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.7?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 65 and take away the sum of its digits. What do you get?
  8. 8.24?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.4?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 67 and take away the sum of its digits. What do you get?
  11. 11.?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.846? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.77? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.58?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?923 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.385? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 32 and take away the sum of its digits. What do you get?
  18. 18.Take 15 and take away the sum of its digits. What do you get?
  19. 19.Take 17 and take away the sum of its digits. What do you get?
  20. 20.66?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.45?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?165 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.8?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.34?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.9?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.6?71 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.61?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.4?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?346 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.199? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?332 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.34?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.297? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 11 and take away the sum of its digits. What do you get?
  35. 35.Take 45 and take away the sum of its digits. What do you get?
  36. 36.Take 85 and take away the sum of its digits. What do you get?
  37. 37.303? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.88?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.158? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 36 and take away the sum of its digits. What do you get?

Answer key

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

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