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Digit Sum Magic Worksheet

Maths tricks trick 10: Digit-sum magic · Set 134 · 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. 1.7?38 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  2. 2.?773 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  3. 3.802? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  4. 4.?845 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  5. 5.432? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  6. 6.880? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  7. 7.2?82 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  8. 8.Take 15 and take away the sum of its digits. What do you get?
  9. 9.Take 22 and take away the sum of its digits. What do you get?
  10. 10.29?3 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  11. 11.?079 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  12. 12.4?17 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  13. 13.Take 80 and take away the sum of its digits. What do you get?
  14. 14.332? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  15. 15.?354 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  16. 16.Take 26 and take away the sum of its digits. What do you get?
  17. 17.?57 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  18. 18.72?7 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  19. 19.?151 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  20. 20.?966 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  21. 21.Take 96 and take away the sum of its digits. What do you get?
  22. 22.144? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  23. 23.Take 85 and take away the sum of its digits. What do you get?
  24. 24.?863 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  25. 25.?598 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  26. 26.Take 37 and take away the sum of its digits. What do you get?
  27. 27.Take 47 and take away the sum of its digits. What do you get?
  28. 28.Take 11 and take away the sum of its digits. What do you get?
  29. 29.465? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  30. 30.Take 28 and take away the sum of its digits. What do you get?
  31. 31.Take 55 and take away the sum of its digits. What do you get?
  32. 32.268? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  33. 33.?955 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  34. 34.Take 27 and take away the sum of its digits. What do you get?
  35. 35.163? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  36. 36.750? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  37. 37.?194 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  38. 38.713? is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?
  39. 39.Take 78 and take away the sum of its digits. What do you get?
  40. 40.?400 is in the 9 times table. One digit is hidden, and it is not 0. What is the hidden digit?

Answer key

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

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