← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 542 · 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. 1.38?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 21 and take away the sum of its digits. What do you get?
  3. 3.2?07 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?700 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?992 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?834 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 23 and take away the sum of its digits. What do you get?
  8. 8.?431 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?355 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?141 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?001 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.72?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 88 and take away the sum of its digits. What do you get?
  14. 14.?948 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.124? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.67?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?634 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.668? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 12 and take away the sum of its digits. What do you get?
  20. 20.?007 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 30 and take away the sum of its digits. What do you get?
  22. 22.Take 34 and take away the sum of its digits. What do you get?
  23. 23.Take 51 and take away the sum of its digits. What do you get?
  24. 24.54?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 20 and take away the sum of its digits. What do you get?
  26. 26.Take 56 and take away the sum of its digits. What do you get?
  27. 27.Take 25 and take away the sum of its digits. What do you get?
  28. 28.8?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.1?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 22 and take away the sum of its digits. What do you get?
  31. 31.?856 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.5?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 26 and take away the sum of its digits. What do you get?
  34. 34.665? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 40 and take away the sum of its digits. What do you get?
  36. 36.?538 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.2?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.2?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.52?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.493? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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