← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 489 · 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. 1.356? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 11 and take away the sum of its digits. What do you get?
  3. 3.?901 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.312? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.?161 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?924 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?914 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 14 and take away the sum of its digits. What do you get?
  9. 9.Take 48 and take away the sum of its digits. What do you get?
  10. 10.?309 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.28?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 66 and take away the sum of its digits. What do you get?
  13. 13.75?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.Take 18 and take away the sum of its digits. What do you get?
  15. 15.24?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.?479 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.866? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.Take 87 and take away the sum of its digits. What do you get?
  19. 19.Take 60 and take away the sum of its digits. What do you get?
  20. 20.Take 57 and take away the sum of its digits. What do you get?
  21. 21.?065 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.620? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 45 and take away the sum of its digits. What do you get?
  24. 24.Take 13 and take away the sum of its digits. What do you get?
  25. 25.1?45 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.8?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 92 and take away the sum of its digits. What do you get?
  28. 28.234? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.80?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 70 and take away the sum of its digits. What do you get?
  31. 31.Take 12 and take away the sum of its digits. What do you get?
  32. 32.463? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.780? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.50?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?132 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?790 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 21 and take away the sum of its digits. What do you get?
  38. 38.400? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.36?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.70?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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