← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 591 · 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.?868 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 26 and take away the sum of its digits. What do you get?
  3. 3.Take 37 and take away the sum of its digits. What do you get?
  4. 4.Take 21 and take away the sum of its digits. What do you get?
  5. 5.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 91 and take away the sum of its digits. What do you get?
  7. 7.?510 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 20 and take away the sum of its digits. What do you get?
  10. 10.Take 35 and take away the sum of its digits. What do you get?
  11. 11.?205 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?980 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.1?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.76?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 95 and take away the sum of its digits. What do you get?
  16. 16.89?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.3?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.573? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.41?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.218? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.17? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 30 and take away the sum of its digits. What do you get?
  23. 23.Take 65 and take away the sum of its digits. What do you get?
  24. 24.19?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.623? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.245? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.88?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.19?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 62 and take away the sum of its digits. What do you get?
  30. 30.8?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.43?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 41 and take away the sum of its digits. What do you get?
  33. 33.182? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 13 and take away the sum of its digits. What do you get?
  35. 35.Take 68 and take away the sum of its digits. What do you get?
  36. 36.73?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 52 and take away the sum of its digits. What do you get?
  38. 38.?033 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 19 and take away the sum of its digits. What do you get?
  40. 40.65?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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