← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 779 · 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. 1.591? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.7?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 78 and take away the sum of its digits. What do you get?
  4. 4.7?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 46 and take away the sum of its digits. What do you get?
  6. 6.Take 70 and take away the sum of its digits. What do you get?
  7. 7.Take 82 and take away the sum of its digits. What do you get?
  8. 8.?136 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 65 and take away the sum of its digits. What do you get?
  10. 10.?905 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.1?97 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 74 and take away the sum of its digits. What do you get?
  13. 13.8?39 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.37?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 49 and take away the sum of its digits. What do you get?
  16. 16.43? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.836? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?821 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?368 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.691? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.54?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.548? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 17 and take away the sum of its digits. What do you get?
  24. 24.Take 24 and take away the sum of its digits. What do you get?
  25. 25.41?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.1?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 87 and take away the sum of its digits. What do you get?
  28. 28.Take 66 and take away the sum of its digits. What do you get?
  29. 29.Take 13 and take away the sum of its digits. What do you get?
  30. 30.Take 26 and take away the sum of its digits. What do you get?
  31. 31.31? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.58?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 51 and take away the sum of its digits. What do you get?
  34. 34.?107 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?841 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.1?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.25?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 96 and take away the sum of its digits. What do you get?
  39. 39.Take 69 and take away the sum of its digits. What do you get?
  40. 40.?200 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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