← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 140 · 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.?386 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 34 and take away the sum of its digits. What do you get?
  3. 3.Take 27 and take away the sum of its digits. What do you get?
  4. 4.?388 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 54 and take away the sum of its digits. What do you get?
  6. 6.47?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 76 and take away the sum of its digits. What do you get?
  8. 8.Take 82 and take away the sum of its digits. What do you get?
  9. 9.397? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 31 and take away the sum of its digits. What do you get?
  11. 11.Take 60 and take away the sum of its digits. What do you get?
  12. 12.Take 89 and take away the sum of its digits. What do you get?
  13. 13.?97 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.48?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.70?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 50 and take away the sum of its digits. What do you get?
  17. 17.6?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?094 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.19?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?454 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 12 and take away the sum of its digits. What do you get?
  22. 22.36?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.9?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.45?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 98 and take away the sum of its digits. What do you get?
  26. 26.Take 48 and take away the sum of its digits. What do you get?
  27. 27.?580 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 43 and take away the sum of its digits. What do you get?
  29. 29.?029 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 28 and take away the sum of its digits. What do you get?
  31. 31.2?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?184 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 21 and take away the sum of its digits. What do you get?
  34. 34.Take 16 and take away the sum of its digits. What do you get?
  35. 35.?674 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.182? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 46 and take away the sum of its digits. What do you get?
  38. 38.Take 38 and take away the sum of its digits. What do you get?
  39. 39.896? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.2?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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