Does the size of a 町 determine if it is pronounced machi or chou? and The first one is pronounced Chatanchou and the second is Shitamachi. The second term is within an area of the the first one. Is a machi smaller than a chou? In the past was the term used in between the kanji to indicate a machi, for example shita no machi?

In the east of Japan, Machi is used more often.
In the west, Cho is used more often.
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