← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 900 · 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.?114 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.3?18 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.Take 80 and take away the sum of its digits. What do you get?
  4. 4.Take 96 and take away the sum of its digits. What do you get?
  5. 5.2?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.69?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 54 and take away the sum of its digits. What do you get?
  8. 8.Take 17 and take away the sum of its digits. What do you get?
  9. 9.?069 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?830 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.Take 73 and take away the sum of its digits. What do you get?
  12. 12.Take 23 and take away the sum of its digits. What do you get?
  13. 13.?033 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.1?78 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.1?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.5?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 24 and take away the sum of its digits. What do you get?
  18. 18.Take 95 and take away the sum of its digits. What do you get?
  19. 19.684? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 67 and take away the sum of its digits. What do you get?
  21. 21.70? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 87 and take away the sum of its digits. What do you get?
  23. 23.27?1 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.5?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 30 and take away the sum of its digits. What do you get?
  26. 26.8?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.609? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.Take 86 and take away the sum of its digits. What do you get?
  29. 29.6?96 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.114? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.?924 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?307 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 34 and take away the sum of its digits. What do you get?
  34. 34.Take 35 and take away the sum of its digits. What do you get?
  35. 35.51?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.631? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.45?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.587? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?383 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.9?7 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. 6
  3. 72
  4. 81
  5. 5
  6. 5
  7. 45
  8. 9
  9. 3
  10. 7
  11. 63
  12. 18
  13. 3
  14. 2
  15. 5
  16. 3
  17. 18
  18. 81
  19. 9
  20. 54
  21. 2
  22. 72
  23. 8
  24. 2
  25. 27
  26. 6
  27. 3
  28. 72
  29. 6
  30. 3
  31. 3
  32. 8
  33. 27
  34. 27
  35. 3
  36. 8
  37. 6
  38. 7
  39. 4
  40. 2

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