← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 423 · 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. 1.3?39 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?881 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.254? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.7?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.244? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.7?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.87?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.73?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.204? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 79 and take away the sum of its digits. What do you get?
  11. 11.Take 55 and take away the sum of its digits. What do you get?
  12. 12.639? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 27 and take away the sum of its digits. What do you get?
  14. 14.88? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.352? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.770? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.5?64 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.112? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?370 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?475 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.2?15 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?760 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.660? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 23 and take away the sum of its digits. What do you get?
  25. 25.7?96 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 15 and take away the sum of its digits. What do you get?
  27. 27.Take 52 and take away the sum of its digits. What do you get?
  28. 28.795? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 42 and take away the sum of its digits. What do you get?
  30. 30.8?94 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.785? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 32 and take away the sum of its digits. What do you get?
  33. 33.?858 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 80 and take away the sum of its digits. What do you get?
  35. 35.3?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.4?65 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.5?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 90 and take away the sum of its digits. What do you get?
  39. 39.Take 44 and take away the sum of its digits. What do you get?
  40. 40.?05 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. 1
  3. 7
  4. 9
  5. 8
  6. 5
  7. 4
  8. 2
  9. 3
  10. 63
  11. 45
  12. 9
  13. 18
  14. 2
  15. 8
  16. 4
  17. 3
  18. 5
  19. 8
  20. 2
  21. 1
  22. 5
  23. 6
  24. 18
  25. 5
  26. 9
  27. 45
  28. 6
  29. 36
  30. 6
  31. 7
  32. 27
  33. 6
  34. 72
  35. 8
  36. 3
  37. 3
  38. 81
  39. 36
  40. 4

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