Meanings
Usage patterns
〈数〉人中〈数〉人X out of Y people
20 out of the 30 students in the class are girls.
〈時〉中にby the end of; within (a time period)
Please reply by the end of this week.
〈事〉中にwhile in the middle of (an activity)
The phone rang while I was in a meeting.
中〈数〉nth-year junior high student
My son is in his second year of junior high.
中を取るto meet halfway; find a compromise
Since the two of them disagreed, they compromised on a middle path.