← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 757 · 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. 1.1?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.25?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 41 and take away the sum of its digits. What do you get?
  4. 4.Take 30 and take away the sum of its digits. What do you get?
  5. 5.7?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 26 and take away the sum of its digits. What do you get?
  7. 7.?582 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.3?64 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 28 and take away the sum of its digits. What do you get?
  10. 10.Take 29 and take away the sum of its digits. What do you get?
  11. 11.19?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 71 and take away the sum of its digits. What do you get?
  13. 13.205? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?996 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 80 and take away the sum of its digits. What do you get?
  17. 17.?897 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.30?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 70 and take away the sum of its digits. What do you get?
  20. 20.?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?605 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?651 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?446 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?709 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 20 and take away the sum of its digits. What do you get?
  27. 27.?290 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?530 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.199? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.299? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.27?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.89?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 96 and take away the sum of its digits. What do you get?
  34. 34.2?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 69 and take away the sum of its digits. What do you get?
  36. 36.1?58 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.2?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 11 and take away the sum of its digits. What do you get?
  39. 39.?047 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.8?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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