← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 991 · 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.?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 39 and take away the sum of its digits. What do you get?
  3. 3.Take 40 and take away the sum of its digits. What do you get?
  4. 4.Take 63 and take away the sum of its digits. What do you get?
  5. 5.35?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.628? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.7?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 71 and take away the sum of its digits. What do you get?
  9. 9.Take 53 and take away the sum of its digits. What do you get?
  10. 10.Take 13 and take away the sum of its digits. What do you get?
  11. 11.Take 27 and take away the sum of its digits. What do you get?
  12. 12.67?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.306? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?723 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?961 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 95 and take away the sum of its digits. What do you get?
  17. 17.510? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 79 and take away the sum of its digits. What do you get?
  19. 19.?403 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.18?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.157? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 20 and take away the sum of its digits. What do you get?
  23. 23.?443 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.47?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?254 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.9?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?904 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 23 and take away the sum of its digits. What do you get?
  29. 29.Take 49 and take away the sum of its digits. What do you get?
  30. 30.28?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.97? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.62?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.61? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 59 and take away the sum of its digits. What do you get?
  35. 35.?707 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 33 and take away the sum of its digits. What do you get?
  37. 37.54?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.6?72 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.8?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 44 and take away the sum of its digits. What do you get?

Answer key

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

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