← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 157 · 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. 1.77? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.237? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.822? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.25?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 64 and take away the sum of its digits. What do you get?
  6. 6.Take 98 and take away the sum of its digits. What do you get?
  7. 7.?500 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.830? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 87 and take away the sum of its digits. What do you get?
  10. 10.2?53 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.31?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.493? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 95 and take away the sum of its digits. What do you get?
  14. 14.Take 83 and take away the sum of its digits. What do you get?
  15. 15.Take 56 and take away the sum of its digits. What do you get?
  16. 16.72?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.793? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?163 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.5?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.1?61 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.80?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 28 and take away the sum of its digits. What do you get?
  23. 23.19?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 17 and take away the sum of its digits. What do you get?
  25. 25.16?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 11 and take away the sum of its digits. What do you get?
  27. 27.Take 68 and take away the sum of its digits. What do you get?
  28. 28.52?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.5?62 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.150? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.7?19 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.270? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 51 and take away the sum of its digits. What do you get?
  34. 34.?683 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.Take 43 and take away the sum of its digits. What do you get?
  36. 36.4?77 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 81 and take away the sum of its digits. What do you get?
  38. 38.756? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.7?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 41 and take away the sum of its digits. What do you get?

Answer key

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

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