← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 939 · 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. 1.10?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 79 and take away the sum of its digits. What do you get?
  3. 3.Take 16 and take away the sum of its digits. What do you get?
  4. 4.Take 81 and take away the sum of its digits. What do you get?
  5. 5.?635 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 73 and take away the sum of its digits. What do you get?
  7. 7.3?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.3?56 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.2?54 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 19 and take away the sum of its digits. What do you get?
  11. 11.?012 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 48 and take away the sum of its digits. What do you get?
  13. 13.?210 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.1?96 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.5?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?020 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.1?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 14 and take away the sum of its digits. What do you get?
  19. 19.Take 83 and take away the sum of its digits. What do you get?
  20. 20.67?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 33 and take away the sum of its digits. What do you get?
  22. 22.407? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.6?11 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?293 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 34 and take away the sum of its digits. What do you get?
  26. 26.5?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.3?86 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.57?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?985 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.587? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?669 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.2?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.4?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 18 and take away the sum of its digits. What do you get?
  35. 35.?817 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?637 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?401 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.17?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.28?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?376 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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