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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 330 · 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 75 and take away the sum of its digits. What do you get?
  2. 2.Take 66 and take away the sum of its digits. What do you get?
  3. 3.Take 94 and take away the sum of its digits. What do you get?
  4. 4.Take 78 and take away the sum of its digits. What do you get?
  5. 5.Take 32 and take away the sum of its digits. What do you get?
  6. 6.793? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.565? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.34?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  9. 9.?496 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  10. 10.Take 35 and take away the sum of its digits. What do you get?
  11. 11.?01 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.7?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.?223 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  14. 14.51?0 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.32?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.3?30 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  17. 17.Take 23 and take away the sum of its digits. What do you get?
  18. 18.Take 88 and take away the sum of its digits. What do you get?
  19. 19.?751 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?40 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.?20 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  22. 22.?54 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 31 and take away the sum of its digits. What do you get?
  24. 24.Take 29 and take away the sum of its digits. What do you get?
  25. 25.?651 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 45 and take away the sum of its digits. What do you get?
  27. 27.Take 17 and take away the sum of its digits. What do you get?
  28. 28.337? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  29. 29.5?92 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 24 and take away the sum of its digits. What do you get?
  31. 31.?070 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  32. 32.80?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?84 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.63?9 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  35. 35.84?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.30?4 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.3?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.72?6 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.469? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  40. 40.?299 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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