← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 736 · 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 96 and take away the sum of its digits. What do you get?
  2. 2.89?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.740? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 57 and take away the sum of its digits. What do you get?
  5. 5.2?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.2?56 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.626? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.803? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 21 and take away the sum of its digits. What do you get?
  11. 11.14?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 72 and take away the sum of its digits. What do you get?
  13. 13.Take 98 and take away the sum of its digits. What do you get?
  14. 14.76?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 44 and take away the sum of its digits. What do you get?
  16. 16.880? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.62?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.193? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 82 and take away the sum of its digits. What do you get?
  20. 20.Take 71 and take away the sum of its digits. What do you get?
  21. 21.?885 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?344 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?098 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 74 and take away the sum of its digits. What do you get?
  25. 25.Take 31 and take away the sum of its digits. What do you get?
  26. 26.?25 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.20? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?991 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 77 and take away the sum of its digits. What do you get?
  30. 30.Take 79 and take away the sum of its digits. What do you get?
  31. 31.Take 64 and take away the sum of its digits. What do you get?
  32. 32.?454 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.14?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.?923 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?836 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 37 and take away the sum of its digits. What do you get?
  37. 37.?39 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 58 and take away the sum of its digits. What do you get?
  39. 39.Take 32 and take away the sum of its digits. What do you get?
  40. 40.Take 28 and take away the sum of its digits. What do you get?

Answer key

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

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