Then vs. than

Look at the following sentences. The sentences contain the words then or than. Try to find a pattern and see if you can discover when you should use then or when you should use than.
 

I like you more than I like him.
He spent more money than he did last month.
She is taller than her sister.

 

He did his homework, then he watched a movie.
Turn left, then turn right after 50 meters.
She is going to the store and then she'll go home.