← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 345 · 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 56 and take away the sum of its digits. What do you get?
  2. 2.?305 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 98 and take away the sum of its digits. What do you get?
  4. 4.2?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.3?98 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.11?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 79 and take away the sum of its digits. What do you get?
  9. 9.Take 85 and take away the sum of its digits. What do you get?
  10. 10.682? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.8?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 41 and take away the sum of its digits. What do you get?
  13. 13.?777 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.758? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 23 and take away the sum of its digits. What do you get?
  16. 16.Take 48 and take away the sum of its digits. What do you get?
  17. 17.23?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.12?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 63 and take away the sum of its digits. What do you get?
  20. 20.?311 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 73 and take away the sum of its digits. What do you get?
  22. 22.?451 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.2?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.190? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?056 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.70?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 25 and take away the sum of its digits. What do you get?
  28. 28.Take 61 and take away the sum of its digits. What do you get?
  29. 29.Take 49 and take away the sum of its digits. What do you get?
  30. 30.210? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 37 and take away the sum of its digits. What do you get?
  32. 32.673? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.68?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.30?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 52 and take away the sum of its digits. What do you get?
  36. 36.92? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 76 and take away the sum of its digits. What do you get?
  38. 38.?077 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.8?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?726 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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