← Digit-sum magic lesson New set →

Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 672 · 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 85 and take away the sum of its digits. What do you get?
  2. 2.Take 33 and take away the sum of its digits. What do you get?
  3. 3.Take 46 and take away the sum of its digits. What do you get?
  4. 4.338? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.Take 80 and take away the sum of its digits. What do you get?
  6. 6.?52 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.Take 63 and take away the sum of its digits. What do you get?
  8. 8.?725 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 84 and take away the sum of its digits. What do you get?
  10. 10.Take 19 and take away the sum of its digits. What do you get?
  11. 11.1?24 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 12 and take away the sum of its digits. What do you get?
  13. 13.57?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.426? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.172? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.1?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 71 and take away the sum of its digits. What do you get?
  18. 18.Take 25 and take away the sum of its digits. What do you get?
  19. 19.59?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.7?39 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?232 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?70 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.8?93 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.Take 49 and take away the sum of its digits. What do you get?
  25. 25.Take 39 and take away the sum of its digits. What do you get?
  26. 26.Take 18 and take away the sum of its digits. What do you get?
  27. 27.Take 90 and take away the sum of its digits. What do you get?
  28. 28.Take 89 and take away the sum of its digits. What do you get?
  29. 29.51?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.1?89 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  31. 31.45? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.Take 74 and take away the sum of its digits. What do you get?
  33. 33.Take 14 and take away the sum of its digits. What do you get?
  34. 34.Take 50 and take away the sum of its digits. What do you get?
  35. 35.631? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.5?94 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.2?68 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.Take 64 and take away the sum of its digits. What do you get?
  39. 39.6?02 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.Take 75 and take away the sum of its digits. What do you get?

Answer key

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

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