← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 847 · 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.Take 68 and take away the sum of its digits. What do you get?
  2. 2.118? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.7?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 92 and take away the sum of its digits. What do you get?
  5. 5.Take 11 and take away the sum of its digits. What do you get?
  6. 6.1?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.687? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.87?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?812 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 80 and take away the sum of its digits. What do you get?
  11. 11.Take 87 and take away the sum of its digits. What do you get?
  12. 12.?060 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.93? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?159 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.196? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.237? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 99 and take away the sum of its digits. What do you get?
  18. 18.65?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 66 and take away the sum of its digits. What do you get?
  20. 20.Take 16 and take away the sum of its digits. What do you get?
  21. 21.Take 27 and take away the sum of its digits. What do you get?
  22. 22.Take 73 and take away the sum of its digits. What do you get?
  23. 23.792? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 98 and take away the sum of its digits. What do you get?
  25. 25.70?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?871 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?05 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.61?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.5?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 26 and take away the sum of its digits. What do you get?
  31. 31.Take 69 and take away the sum of its digits. What do you get?
  32. 32.134? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 33 and take away the sum of its digits. What do you get?
  34. 34.317? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.640? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 67 and take away the sum of its digits. What do you get?
  37. 37.Take 63 and take away the sum of its digits. What do you get?
  38. 38.Take 56 and take away the sum of its digits. What do you get?
  39. 39.359? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?859 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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