← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 443 · 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. 1.2?09 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?943 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.712? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.1?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 62 and take away the sum of its digits. What do you get?
  6. 6.Take 31 and take away the sum of its digits. What do you get?
  7. 7.?74 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.332? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.7?42 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 15 and take away the sum of its digits. What do you get?
  11. 11.2?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.41?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 73 and take away the sum of its digits. What do you get?
  14. 14.409? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.3?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.564? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.2?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.238? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 79 and take away the sum of its digits. What do you get?
  20. 20.61? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.28?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 56 and take away the sum of its digits. What do you get?
  23. 23.Take 57 and take away the sum of its digits. What do you get?
  24. 24.645? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 40 and take away the sum of its digits. What do you get?
  26. 26.89?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.293? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 85 and take away the sum of its digits. What do you get?
  30. 30.52?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.Take 86 and take away the sum of its digits. What do you get?
  32. 32.?690 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.4?96 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 45 and take away the sum of its digits. What do you get?
  35. 35.6?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.4?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.60?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 87 and take away the sum of its digits. What do you get?
  39. 39.Take 33 and take away the sum of its digits. What do you get?
  40. 40.?079 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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