← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 889 · 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.?26 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?74 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 18 and take away the sum of its digits. What do you get?
  4. 4.30?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.22?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.58?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?650 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 75 and take away the sum of its digits. What do you get?
  9. 9.383? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 86 and take away the sum of its digits. What do you get?
  11. 11.2?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.837? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 69 and take away the sum of its digits. What do you get?
  14. 14.?838 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?616 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.6?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.512? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.107? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?143 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.4?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.75?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 47 and take away the sum of its digits. What do you get?
  23. 23.?915 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.5?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 50 and take away the sum of its digits. What do you get?
  26. 26.295? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.41?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.4?63 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.188? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.5?58 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?367 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.494? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.202? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.42?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?102 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 16 and take away the sum of its digits. What do you get?
  37. 37.184? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.7?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.10?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?987 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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