← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 29 · 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 43 and take away the sum of its digits. What do you get?
  2. 2.?371 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.739? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.143? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 67 and take away the sum of its digits. What do you get?
  6. 6.Take 17 and take away the sum of its digits. What do you get?
  7. 7.Take 20 and take away the sum of its digits. What do you get?
  8. 8.69?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.4?58 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.219? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.24?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 53 and take away the sum of its digits. What do you get?
  13. 13.544? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 84 and take away the sum of its digits. What do you get?
  15. 15.Take 33 and take away the sum of its digits. What do you get?
  16. 16.113? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.72? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 80 and take away the sum of its digits. What do you get?
  19. 19.?341 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 73 and take away the sum of its digits. What do you get?
  21. 21.Take 15 and take away the sum of its digits. What do you get?
  22. 22.Take 98 and take away the sum of its digits. What do you get?
  23. 23.4?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 48 and take away the sum of its digits. What do you get?
  25. 25.Take 74 and take away the sum of its digits. What do you get?
  26. 26.?238 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.1?69 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?146 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 16 and take away the sum of its digits. What do you get?
  30. 30.Take 76 and take away the sum of its digits. What do you get?
  31. 31.?429 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 28 and take away the sum of its digits. What do you get?
  33. 33.78?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.66?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.305? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.Take 54 and take away the sum of its digits. What do you get?
  37. 37.1?23 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.56?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 13 and take away the sum of its digits. What do you get?
  40. 40.Take 29 and take away the sum of its digits. What do you get?

Answer key

  1. 36
  2. 7
  3. 8
  4. 1
  5. 54
  6. 9
  7. 18
  8. 7
  9. 1
  10. 6
  11. 5
  12. 45
  13. 5
  14. 72
  15. 27
  16. 4
  17. 9
  18. 72
  19. 1
  20. 63
  21. 9
  22. 81
  23. 1
  24. 36
  25. 63
  26. 5
  27. 2
  28. 7
  29. 9
  30. 63
  31. 3
  32. 18
  33. 7
  34. 6
  35. 1
  36. 45
  37. 3
  38. 2
  39. 9
  40. 18

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