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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 25 · 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. 1.63?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.Take 18 and take away the sum of its digits. What do you get?
  3. 3.738? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?343 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.75?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.334? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.?076 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.?514 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.Take 33 and take away the sum of its digits. What do you get?
  10. 10.?582 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.358? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.Take 62 and take away the sum of its digits. What do you get?
  13. 13.Take 72 and take away the sum of its digits. What do you get?
  14. 14.20?8 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.32?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.3?98 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.65?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.?49 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?186 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.Take 47 and take away the sum of its digits. What do you get?
  21. 21.?181 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.Take 56 and take away the sum of its digits. What do you get?
  23. 23.67?5 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  24. 24.20?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.326? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 66 and take away the sum of its digits. What do you get?
  27. 27.Take 73 and take away the sum of its digits. What do you get?
  28. 28.3?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.Take 32 and take away the sum of its digits. What do you get?
  30. 30.Take 85 and take away the sum of its digits. What do you get?
  31. 31.181? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.?141 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?222 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.4?79 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.7?66 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.7?75 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.62?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.54?2 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 70 and take away the sum of its digits. What do you get?
  40. 40.Take 25 and take away the sum of its digits. What do you get?

Answer key

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

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