← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 153 · 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 51 and take away the sum of its digits. What do you get?
  2. 2.Take 94 and take away the sum of its digits. What do you get?
  3. 3.Take 50 and take away the sum of its digits. What do you get?
  4. 4.1?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?471 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.210? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 18 and take away the sum of its digits. What do you get?
  8. 8.8?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.101? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?565 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 33 and take away the sum of its digits. What do you get?
  12. 12.Take 70 and take away the sum of its digits. What do you get?
  13. 13.Take 31 and take away the sum of its digits. What do you get?
  14. 14.7?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 65 and take away the sum of its digits. What do you get?
  16. 16.7?49 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 92 and take away the sum of its digits. What do you get?
  18. 18.368? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 71 and take away the sum of its digits. What do you get?
  20. 20.Take 83 and take away the sum of its digits. What do you get?
  21. 21.Take 76 and take away the sum of its digits. What do you get?
  22. 22.Take 63 and take away the sum of its digits. What do you get?
  23. 23.?548 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 79 and take away the sum of its digits. What do you get?
  26. 26.32?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.188? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.875? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.28?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?85 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 90 and take away the sum of its digits. What do you get?
  32. 32.7?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?177 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.382? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 52 and take away the sum of its digits. What do you get?
  36. 36.Take 60 and take away the sum of its digits. What do you get?
  37. 37.83? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.7?71 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 54 and take away the sum of its digits. What do you get?
  40. 40.?685 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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