← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 671 · 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 73 and take away the sum of its digits. What do you get?
  2. 2.30?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.101? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 37 and take away the sum of its digits. What do you get?
  6. 6.21?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.7?74 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 71 and take away the sum of its digits. What do you get?
  9. 9.Take 29 and take away the sum of its digits. What do you get?
  10. 10.730? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?843 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.?699 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 31 and take away the sum of its digits. What do you get?
  14. 14.394? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.8?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?47 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?908 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?048 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.221? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 24 and take away the sum of its digits. What do you get?
  22. 22.507? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?681 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.195? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.5?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.85?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.8?45 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 91 and take away the sum of its digits. What do you get?
  29. 29.889? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.?120 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 56 and take away the sum of its digits. What do you get?
  32. 32.Take 78 and take away the sum of its digits. What do you get?
  33. 33.42?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.6?60 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.5?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 98 and take away the sum of its digits. What do you get?
  37. 37.Take 63 and take away the sum of its digits. What do you get?
  38. 38.81?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 44 and take away the sum of its digits. What do you get?
  40. 40.506? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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