← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 310 · 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.?046 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.210? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.7?33 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.8?48 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.69?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.Take 48 and take away the sum of its digits. What do you get?
  7. 7.878? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 84 and take away the sum of its digits. What do you get?
  9. 9.4?88 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.?004 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.5?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 92 and take away the sum of its digits. What do you get?
  13. 13.829? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.492? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.3?83 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.586? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.71?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.500? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.Take 88 and take away the sum of its digits. What do you get?
  20. 20.?03 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?274 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 81 and take away the sum of its digits. What do you get?
  23. 23.Take 94 and take away the sum of its digits. What do you get?
  24. 24.42?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.?975 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  27. 27.Take 28 and take away the sum of its digits. What do you get?
  28. 28.Take 20 and take away the sum of its digits. What do you get?
  29. 29.11?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 39 and take away the sum of its digits. What do you get?
  31. 31.76?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 63 and take away the sum of its digits. What do you get?
  33. 33.Take 90 and take away the sum of its digits. What do you get?
  34. 34.6?80 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.?705 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.?650 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.42?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 42 and take away the sum of its digits. What do you get?
  39. 39.Take 22 and take away the sum of its digits. What do you get?
  40. 40.759? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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