← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 146 · 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 27 and take away the sum of its digits. What do you get?
  2. 2.36?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.540? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.8?72 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.362? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 45 and take away the sum of its digits. What do you get?
  7. 7.8?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.21?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 31 and take away the sum of its digits. What do you get?
  10. 10.Take 38 and take away the sum of its digits. What do you get?
  11. 11.Take 94 and take away the sum of its digits. What do you get?
  12. 12.Take 78 and take away the sum of its digits. What do you get?
  13. 13.?357 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.442? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.44?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?066 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?47 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 56 and take away the sum of its digits. What do you get?
  19. 19.1?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.556? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.839? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.35?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 21 and take away the sum of its digits. What do you get?
  24. 24.?952 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?474 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?051 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?503 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 16 and take away the sum of its digits. What do you get?
  29. 29.Take 17 and take away the sum of its digits. What do you get?
  30. 30.?488 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 34 and take away the sum of its digits. What do you get?
  32. 32.26?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.4?11 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.2?72 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?140 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.879? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?413 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.42?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?219 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.54?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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