← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 27 · 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 22 and take away the sum of its digits. What do you get?
  2. 2.?319 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.6?32 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.Take 72 and take away the sum of its digits. What do you get?
  5. 5.Take 88 and take away the sum of its digits. What do you get?
  6. 6.4?29 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.4?41 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.16?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 63 and take away the sum of its digits. What do you get?
  10. 10.Take 25 and take away the sum of its digits. What do you get?
  11. 11.Take 29 and take away the sum of its digits. What do you get?
  12. 12.Take 83 and take away the sum of its digits. What do you get?
  13. 13.?534 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?867 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.834? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 36 and take away the sum of its digits. What do you get?
  17. 17.Take 95 and take away the sum of its digits. What do you get?
  18. 18.20?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.25?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?539 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?962 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.1?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 21 and take away the sum of its digits. What do you get?
  24. 24.260? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.Take 46 and take away the sum of its digits. What do you get?
  26. 26.8?36 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.7?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.?210 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.?806 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 66 and take away the sum of its digits. What do you get?
  31. 31.?111 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?167 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.Take 96 and take away the sum of its digits. What do you get?
  34. 34.?23 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?46 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?618 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.Take 31 and take away the sum of its digits. What do you get?
  38. 38.139? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.?785 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.725? 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. 7
  4. 63
  5. 72
  6. 3
  7. 9
  8. 2
  9. 54
  10. 18
  11. 18
  12. 72
  13. 6
  14. 6
  15. 3
  16. 27
  17. 81
  18. 2
  19. 3
  20. 1
  21. 1
  22. 4
  23. 18
  24. 1
  25. 36
  26. 1
  27. 8
  28. 6
  29. 4
  30. 54
  31. 6
  32. 4
  33. 81
  34. 4
  35. 8
  36. 3
  37. 27
  38. 5
  39. 7
  40. 4

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