← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 716 · 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. 1.641? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 84 and take away the sum of its digits. What do you get?
  3. 3.297? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 96 and take away the sum of its digits. What do you get?
  5. 5.Take 28 and take away the sum of its digits. What do you get?
  6. 6.8?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.56?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?192 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.8?64 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 81 and take away the sum of its digits. What do you get?
  11. 11.42?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.4?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 69 and take away the sum of its digits. What do you get?
  14. 14.54?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.8?37 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?411 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 99 and take away the sum of its digits. What do you get?
  18. 18.Take 39 and take away the sum of its digits. What do you get?
  19. 19.Take 12 and take away the sum of its digits. What do you get?
  20. 20.152? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 23 and take away the sum of its digits. What do you get?
  22. 22.?474 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 88 and take away the sum of its digits. What do you get?
  24. 24.?483 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?962 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.7?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 50 and take away the sum of its digits. What do you get?
  28. 28.Take 24 and take away the sum of its digits. What do you get?
  29. 29.?587 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?723 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 83 and take away the sum of its digits. What do you get?
  32. 32.883? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.1?85 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.51?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?919 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 80 and take away the sum of its digits. What do you get?
  37. 37.Take 38 and take away the sum of its digits. What do you get?
  38. 38.2?32 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 41 and take away the sum of its digits. What do you get?
  40. 40.503? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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