← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 5 · 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 66 and take away the sum of its digits. What do you get?
  2. 2.Take 69 and take away the sum of its digits. What do you get?
  3. 3.77?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?772 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 36 and take away the sum of its digits. What do you get?
  7. 7.31?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.2?67 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.3?81 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.64?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.1?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 76 and take away the sum of its digits. What do you get?
  13. 13.8?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.721? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 28 and take away the sum of its digits. What do you get?
  16. 16.Take 82 and take away the sum of its digits. What do you get?
  17. 17.14? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.8?35 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 45 and take away the sum of its digits. What do you get?
  20. 20.Take 51 and take away the sum of its digits. What do you get?
  21. 21.?43 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.674? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 73 and take away the sum of its digits. What do you get?
  24. 24.502? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?029 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?073 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?102 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 44 and take away the sum of its digits. What do you get?
  29. 29.44?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?641 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.7?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?003 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?472 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.24?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?258 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?85 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.4?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?273 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?336 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.8?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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