← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 505 · 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. 1.351? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 27 and take away the sum of its digits. What do you get?
  3. 3.?390 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?943 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.30?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.8?71 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?057 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 18 and take away the sum of its digits. What do you get?
  9. 9.Take 33 and take away the sum of its digits. What do you get?
  10. 10.Take 14 and take away the sum of its digits. What do you get?
  11. 11.3?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.561? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?56 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 84 and take away the sum of its digits. What do you get?
  15. 15.?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.457? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.110? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 90 and take away the sum of its digits. What do you get?
  19. 19.63?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.6?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?951 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.65?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.67?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.431? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.584? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?332 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.627? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?265 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?530 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.65?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?030 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?920 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 70 and take away the sum of its digits. What do you get?
  34. 34.8?91 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 50 and take away the sum of its digits. What do you get?
  36. 36.Take 68 and take away the sum of its digits. What do you get?
  37. 37.Take 34 and take away the sum of its digits. What do you get?
  38. 38.?353 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 67 and take away the sum of its digits. What do you get?
  40. 40.66?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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