I was trying to say "at that time I started to be interested in maths". I translated it as:
Then I saw some other expressions to say "at that time": 那时，那时候，那会儿，那阵子.
What are the differences between those? I suppose 那会儿 is "at that moment" instead of "at that time" but what is the difference with 那时 and 那时候? And what is the meaning of 那阵子?