← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 764 · 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.?236 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 36 and take away the sum of its digits. What do you get?
  3. 3.Take 93 and take away the sum of its digits. What do you get?
  4. 4.Take 69 and take away the sum of its digits. What do you get?
  5. 5.5?13 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.?528 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 58 and take away the sum of its digits. What do you get?
  8. 8.Take 59 and take away the sum of its digits. What do you get?
  9. 9.85?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.81?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.7?71 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.53?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.82?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.?791 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.3?16 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 15 and take away the sum of its digits. What do you get?
  17. 17.Take 91 and take away the sum of its digits. What do you get?
  18. 18.?840 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.8?21 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 22 and take away the sum of its digits. What do you get?
  21. 21.305? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 26 and take away the sum of its digits. What do you get?
  23. 23.Take 11 and take away the sum of its digits. What do you get?
  24. 24.47?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.84?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 56 and take away the sum of its digits. What do you get?
  27. 27.?273 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  28. 28.21?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 77 and take away the sum of its digits. What do you get?
  30. 30.Take 37 and take away the sum of its digits. What do you get?
  31. 31.?851 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.7?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?448 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.77?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?473 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.2?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?357 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.1?11 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 44 and take away the sum of its digits. What do you get?
  40. 40.53?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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