← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 637 · 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.?722 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.12?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.49?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?715 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 63 and take away the sum of its digits. What do you get?
  6. 6.8?87 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.4?56 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.563? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 53 and take away the sum of its digits. What do you get?
  11. 11.?040 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 37 and take away the sum of its digits. What do you get?
  13. 13.?035 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 16 and take away the sum of its digits. What do you get?
  15. 15.?803 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.245? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.2?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?59 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 57 and take away the sum of its digits. What do you get?
  20. 20.497? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.4?18 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.7?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?375 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 23 and take away the sum of its digits. What do you get?
  25. 25.Take 38 and take away the sum of its digits. What do you get?
  26. 26.Take 51 and take away the sum of its digits. What do you get?
  27. 27.Take 65 and take away the sum of its digits. What do you get?
  28. 28.8?35 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.39?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.457? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.17?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?815 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 61 and take away the sum of its digits. What do you get?
  34. 34.872? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 41 and take away the sum of its digits. What do you get?
  36. 36.Take 94 and take away the sum of its digits. What do you get?
  37. 37.Take 55 and take away the sum of its digits. What do you get?
  38. 38.8?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 93 and take away the sum of its digits. What do you get?
  40. 40.Take 12 and take away the sum of its digits. What do you get?

Answer key

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

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