← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 79 · 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. 1.5?55 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?240 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.8?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.41?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 37 and take away the sum of its digits. What do you get?
  6. 6.76?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.14?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.570? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?695 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 55 and take away the sum of its digits. What do you get?
  11. 11.Take 13 and take away the sum of its digits. What do you get?
  12. 12.Take 51 and take away the sum of its digits. What do you get?
  13. 13.?336 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.306? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 33 and take away the sum of its digits. What do you get?
  16. 16.Take 18 and take away the sum of its digits. What do you get?
  17. 17.455? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.561? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?050 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?701 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 59 and take away the sum of its digits. What do you get?
  22. 22.75?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 84 and take away the sum of its digits. What do you get?
  24. 24.544? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 11 and take away the sum of its digits. What do you get?
  26. 26.6?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.472? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 82 and take away the sum of its digits. What do you get?
  29. 29.68?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.8?85 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.774? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.6?35 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?485 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.2?49 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.615? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 21 and take away the sum of its digits. What do you get?
  37. 37.47?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.3?86 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.15?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.558? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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