← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 820 · 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. 1.7?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.864? 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. 4.60?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 98 and take away the sum of its digits. What do you get?
  6. 6.2?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.112? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 90 and take away the sum of its digits. What do you get?
  9. 9.Take 42 and take away the sum of its digits. What do you get?
  10. 10.64?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 12 and take away the sum of its digits. What do you get?
  12. 12.Take 57 and take away the sum of its digits. What do you get?
  13. 13.26?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.874? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.1?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?809 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 39 and take away the sum of its digits. What do you get?
  18. 18.?932 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?032 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 67 and take away the sum of its digits. What do you get?
  21. 21.Take 70 and take away the sum of its digits. What do you get?
  22. 22.46?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 14 and take away the sum of its digits. What do you get?
  24. 24.Take 49 and take away the sum of its digits. What do you get?
  25. 25.Take 31 and take away the sum of its digits. What do you get?
  26. 26.8?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.757? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?301 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 22 and take away the sum of its digits. What do you get?
  30. 30.64?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 74 and take away the sum of its digits. What do you get?
  32. 32.Take 36 and take away the sum of its digits. What do you get?
  33. 33.Take 40 and take away the sum of its digits. What do you get?
  34. 34.?518 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 44 and take away the sum of its digits. What do you get?
  36. 36.Take 69 and take away the sum of its digits. What do you get?
  37. 37.Take 83 and take away the sum of its digits. What do you get?
  38. 38.8?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.5?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.106? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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