← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 818 · 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 20 and take away the sum of its digits. What do you get?
  2. 2.?247 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 97 and take away the sum of its digits. What do you get?
  4. 4.Take 54 and take away the sum of its digits. What do you get?
  5. 5.384? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.141? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 62 and take away the sum of its digits. What do you get?
  8. 8.99? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.41?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 74 and take away the sum of its digits. What do you get?
  11. 11.Take 38 and take away the sum of its digits. What do you get?
  12. 12.51? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?590 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 36 and take away the sum of its digits. What do you get?
  15. 15.?007 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?280 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 39 and take away the sum of its digits. What do you get?
  18. 18.?380 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.18?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 17 and take away the sum of its digits. What do you get?
  21. 21.?202 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.1?06 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.479? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.1?40 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?517 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.36?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.?055 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 76 and take away the sum of its digits. What do you get?
  29. 29.52?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 68 and take away the sum of its digits. What do you get?
  31. 31.79?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?610 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.8?97 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 33 and take away the sum of its digits. What do you get?
  35. 35.6?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.148? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 49 and take away the sum of its digits. What do you get?
  38. 38.?947 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.32?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?913 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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