← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 981 · 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 64 and take away the sum of its digits. What do you get?
  2. 2.?290 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.?978 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?817 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?048 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.7?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.138? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.4?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 88 and take away the sum of its digits. What do you get?
  10. 10.136? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.52?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 68 and take away the sum of its digits. What do you get?
  13. 13.Take 44 and take away the sum of its digits. What do you get?
  14. 14.?352 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.Take 90 and take away the sum of its digits. What do you get?
  16. 16.12? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.36?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.50?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 28 and take away the sum of its digits. What do you get?
  20. 20.27?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?483 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.85?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.?205 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 79 and take away the sum of its digits. What do you get?
  25. 25.?095 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 63 and take away the sum of its digits. What do you get?
  27. 27.1?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?980 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 73 and take away the sum of its digits. What do you get?
  30. 30.Take 17 and take away the sum of its digits. What do you get?
  31. 31.56? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.500? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.2?95 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.?898 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.7?35 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 23 and take away the sum of its digits. What do you get?
  37. 37.?508 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.?391 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 95 and take away the sum of its digits. What do you get?
  40. 40.?430 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

  1. 54
  2. 7
  3. 3
  4. 2
  5. 6
  6. 6
  7. 6
  8. 7
  9. 72
  10. 8
  11. 6
  12. 54
  13. 36
  14. 8
  15. 81
  16. 6
  17. 7
  18. 4
  19. 18
  20. 7
  21. 3
  22. 5
  23. 2
  24. 63
  25. 4
  26. 54
  27. 6
  28. 1
  29. 63
  30. 9
  31. 7
  32. 4
  33. 2
  34. 2
  35. 3
  36. 18
  37. 5
  38. 5
  39. 81
  40. 2

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