Question 4 - BonusThis trick is based on the number of matches in a matchbook.
- Take an unused matchbook that contains 20 matches and tear out any number of matches, up to 9.
- Throw them away and count the matches that remain.
- Add the 2 digits of this number and tear out the same number of matches from the book.
- Tear out 2 more matches
Try this a couple of times. What is the result?
Think of a way to prove the answer will always be the same. You do not need to use algebra if you can find another method.
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