← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 957 · 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. 1.6?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 56 and take away the sum of its digits. What do you get?
  3. 3.782? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 81 and take away the sum of its digits. What do you get?
  5. 5.85?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 47 and take away the sum of its digits. What do you get?
  7. 7.Take 87 and take away the sum of its digits. What do you get?
  8. 8.Take 60 and take away the sum of its digits. What do you get?
  9. 9.128? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?205 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.8?22 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 49 and take away the sum of its digits. What do you get?
  13. 13.5?33 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 43 and take away the sum of its digits. What do you get?
  15. 15.?286 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.66?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.1?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.525? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 51 and take away the sum of its digits. What do you get?
  20. 20.Take 14 and take away the sum of its digits. What do you get?
  21. 21.Take 80 and take away the sum of its digits. What do you get?
  22. 22.120? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?613 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?055 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 71 and take away the sum of its digits. What do you get?
  26. 26.3?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.32?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 91 and take away the sum of its digits. What do you get?
  29. 29.28?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.44?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?645 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 30 and take away the sum of its digits. What do you get?
  33. 33.55?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 22 and take away the sum of its digits. What do you get?
  35. 35.?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.150? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 48 and take away the sum of its digits. What do you get?
  38. 38.Take 29 and take away the sum of its digits. What do you get?
  39. 39.?40 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.146? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 9
  2. 45
  3. 1
  4. 72
  5. 1
  6. 36
  7. 72
  8. 54
  9. 7
  10. 2
  11. 6
  12. 36
  13. 7
  14. 36
  15. 2
  16. 6
  17. 9
  18. 6
  19. 45
  20. 9
  21. 72
  22. 6
  23. 8
  24. 8
  25. 63
  26. 5
  27. 3
  28. 81
  29. 9
  30. 6
  31. 3
  32. 27
  33. 8
  34. 18
  35. 6
  36. 3
  37. 36
  38. 18
  39. 5
  40. 7

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