← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 611 · 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.?718 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.4?44 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 93 and take away the sum of its digits. What do you get?
  4. 4.Take 27 and take away the sum of its digits. What do you get?
  5. 5.Take 13 and take away the sum of its digits. What do you get?
  6. 6.Take 31 and take away the sum of its digits. What do you get?
  7. 7.?215 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?730 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?700 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.115? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.440? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.15?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.1?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.57?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.8?73 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 17 and take away the sum of its digits. What do you get?
  17. 17.Take 81 and take away the sum of its digits. What do you get?
  18. 18.?723 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.13?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?424 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 44 and take away the sum of its digits. What do you get?
  22. 22.408? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 79 and take away the sum of its digits. What do you get?
  24. 24.73? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?34 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 48 and take away the sum of its digits. What do you get?
  27. 27.Take 60 and take away the sum of its digits. What do you get?
  28. 28.19?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.3?37 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.544? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 38 and take away the sum of its digits. What do you get?
  32. 32.19?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 72 and take away the sum of its digits. What do you get?
  34. 34.7?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.6?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 82 and take away the sum of its digits. What do you get?
  37. 37.?629 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 24 and take away the sum of its digits. What do you get?
  39. 39.?50 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?327 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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