← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 26 · 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. 1.67?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.609? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 25 and take away the sum of its digits. What do you get?
  4. 4.62?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.1?14 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 70 and take away the sum of its digits. What do you get?
  7. 7.?701 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.423? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 21 and take away the sum of its digits. What do you get?
  10. 10.1?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 87 and take away the sum of its digits. What do you get?
  12. 12.Take 50 and take away the sum of its digits. What do you get?
  13. 13.45?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 79 and take away the sum of its digits. What do you get?
  15. 15.Take 62 and take away the sum of its digits. What do you get?
  16. 16.?341 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.?746 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 67 and take away the sum of its digits. What do you get?
  19. 19.?190 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?070 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.433? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.7?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 43 and take away the sum of its digits. What do you get?
  24. 24.744? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.18?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.6?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.5?32 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.1?00 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.5?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.251? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.83?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 47 and take away the sum of its digits. What do you get?
  33. 33.?871 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 52 and take away the sum of its digits. What do you get?
  35. 35.3?90 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?759 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.3?12 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.32?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.529? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.3?03 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. 3
  3. 18
  4. 1
  5. 3
  6. 63
  7. 1
  8. 9
  9. 18
  10. 3
  11. 72
  12. 45
  13. 7
  14. 63
  15. 54
  16. 1
  17. 1
  18. 54
  19. 8
  20. 2
  21. 8
  22. 2
  23. 36
  24. 3
  25. 4
  26. 5
  27. 8
  28. 8
  29. 7
  30. 1
  31. 8
  32. 36
  33. 2
  34. 45
  35. 6
  36. 6
  37. 3
  38. 7
  39. 2
  40. 3

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