← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 359 · 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 42 and take away the sum of its digits. What do you get?
  2. 2.1?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.25?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.49?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?767 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.38? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.71?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 14 and take away the sum of its digits. What do you get?
  9. 9.386? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?428 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?987 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.9?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 32 and take away the sum of its digits. What do you get?
  14. 14.?376 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.5?04 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.882? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?815 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.23?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.8?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 92 and take away the sum of its digits. What do you get?
  21. 21.?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 53 and take away the sum of its digits. What do you get?
  23. 23.298? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?163 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 91 and take away the sum of its digits. What do you get?
  26. 26.73?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 47 and take away the sum of its digits. What do you get?
  28. 28.86?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?762 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.487? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 39 and take away the sum of its digits. What do you get?
  32. 32.Take 25 and take away the sum of its digits. What do you get?
  33. 33.Take 23 and take away the sum of its digits. What do you get?
  34. 34.Take 58 and take away the sum of its digits. What do you get?
  35. 35.?166 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 62 and take away the sum of its digits. What do you get?
  37. 37.?730 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.26? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 78 and take away the sum of its digits. What do you get?
  40. 40.Take 20 and take away the sum of its digits. What do you get?

Answer key

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

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