← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 712 · 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 32 and take away the sum of its digits. What do you get?
  2. 2.?030 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.307? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 54 and take away the sum of its digits. What do you get?
  5. 5.Take 64 and take away the sum of its digits. What do you get?
  6. 6.?85 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.79? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 78 and take away the sum of its digits. What do you get?
  9. 9.Take 35 and take away the sum of its digits. What do you get?
  10. 10.?173 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 27 and take away the sum of its digits. What do you get?
  12. 12.2?31 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?048 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?960 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.884? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.64?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?741 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.356? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 94 and take away the sum of its digits. What do you get?
  21. 21.531? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.112? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 42 and take away the sum of its digits. What do you get?
  24. 24.Take 34 and take away the sum of its digits. What do you get?
  25. 25.119? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?547 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 95 and take away the sum of its digits. What do you get?
  28. 28.48?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.85? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 36 and take away the sum of its digits. What do you get?
  31. 31.Take 16 and take away the sum of its digits. What do you get?
  32. 32.3?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?400 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.43?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 77 and take away the sum of its digits. What do you get?
  36. 36.7?43 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?790 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 31 and take away the sum of its digits. What do you get?
  39. 39.364? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?013 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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