Yeah, a contraction is a shortened form of a word.
You see "Holy day" has seven letters and the contraction "holiday" has seven letters...
Ahhh... nevermind.
What are you? Grammar police? Anyway, a contraction sometimes merely eliminates a space, like "does not" becomes "doesn't". Both contain seven characters, but one eliminates the space. Same with "do not" = "don't", "you are" = "you're", etc., etc.
Anyway, I'm sure you'll do well next year in the eleventh grade.
Meanwhile, I hope you're having fun arranging your socks just right or whatever it is you do when you're not picking nits.