← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 293 · 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.?181 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?020 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 21 and take away the sum of its digits. What do you get?
  4. 4.?995 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 90 and take away the sum of its digits. What do you get?
  6. 6.Take 73 and take away the sum of its digits. What do you get?
  7. 7.3?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?321 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 14 and take away the sum of its digits. What do you get?
  10. 10.Take 91 and take away the sum of its digits. What do you get?
  11. 11.?826 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?421 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.13?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 27 and take away the sum of its digits. What do you get?
  15. 15.?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.75?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 22 and take away the sum of its digits. What do you get?
  18. 18.6?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?740 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 45 and take away the sum of its digits. What do you get?
  22. 22.2?51 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.834? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 96 and take away the sum of its digits. What do you get?
  25. 25.Take 23 and take away the sum of its digits. What do you get?
  26. 26.Take 50 and take away the sum of its digits. What do you get?
  27. 27.?64 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?309 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 98 and take away the sum of its digits. What do you get?
  30. 30.Take 68 and take away the sum of its digits. What do you get?
  31. 31.?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 28 and take away the sum of its digits. What do you get?
  33. 33.8?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 70 and take away the sum of its digits. What do you get?
  35. 35.462? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?465 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?439 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.2?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?660 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.17?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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