← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 163 · 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. 1.1?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?640 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?362 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 23 and take away the sum of its digits. What do you get?
  6. 6.236? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?741 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.72?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.48? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.3?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.17?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.497? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 34 and take away the sum of its digits. What do you get?
  14. 14.85?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?308 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.8?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 95 and take away the sum of its digits. What do you get?
  18. 18.833? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.7?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?726 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.1?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.6?84 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 44 and take away the sum of its digits. What do you get?
  24. 24.Take 70 and take away the sum of its digits. What do you get?
  25. 25.Take 78 and take away the sum of its digits. What do you get?
  26. 26.64?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 20 and take away the sum of its digits. What do you get?
  28. 28.48?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 18 and take away the sum of its digits. What do you get?
  30. 30.474? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 98 and take away the sum of its digits. What do you get?
  32. 32.25?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?77 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 83 and take away the sum of its digits. What do you get?
  35. 35.274? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 57 and take away the sum of its digits. What do you get?
  37. 37.Take 66 and take away the sum of its digits. What do you get?
  38. 38.Take 90 and take away the sum of its digits. What do you get?
  39. 39.610? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.1?77 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. 8
  3. 7
  4. 6
  5. 18
  6. 7
  7. 6
  8. 7
  9. 6
  10. 1
  11. 4
  12. 7
  13. 27
  14. 1
  15. 7
  16. 6
  17. 81
  18. 4
  19. 3
  20. 3
  21. 8
  22. 9
  23. 36
  24. 63
  25. 63
  26. 9
  27. 18
  28. 1
  29. 9
  30. 3
  31. 81
  32. 2
  33. 4
  34. 72
  35. 5
  36. 45
  37. 54
  38. 81
  39. 2
  40. 3

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