← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 432 · 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. 1.1?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?28 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.6?22 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 14 and take away the sum of its digits. What do you get?
  6. 6.Take 83 and take away the sum of its digits. What do you get?
  7. 7.Take 87 and take away the sum of its digits. What do you get?
  8. 8.Take 94 and take away the sum of its digits. What do you get?
  9. 9.?121 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.303? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.297? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.54? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 80 and take away the sum of its digits. What do you get?
  15. 15.Take 67 and take away the sum of its digits. What do you get?
  16. 16.8?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.6?94 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.1?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.28?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.71?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.3?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 74 and take away the sum of its digits. What do you get?
  24. 24.708? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?959 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.76?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?890 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.818? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.32?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.20?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.4?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.1?96 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 90 and take away the sum of its digits. What do you get?
  34. 34.Take 37 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. 36.332? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 44 and take away the sum of its digits. What do you get?
  38. 38.546? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 53 and take away the sum of its digits. What do you get?
  40. 40.Take 66 and take away the sum of its digits. What do you get?

Answer key

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

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