1A rate, ratio, or proportion relative to the whole.
この学校で留学生の割は年々増えている。
The proportion of international students at this school is increasing year by year.
女性の割が多い職場で働いている。
I work at a workplace where women make up a large proportion of the staff.
賛成した人の割はそれほど高くなかった。
The proportion of people who agreed wasn't all that high.
2The unit wari, where one wari equals ten percent, as in 二割 (20%) or 三割 (30%).
今年の売り上げは去年より二割増えた。
This year's sales increased by 20% over last year.
このシャツは元値の三割引で買えた。
I was able to buy this shirt at 30% off the original price.
打率が三割を超える選手はそう多くない。
There aren't that many players with a batting average over .300.
3Worth or profitability relative to effort or cost, used in expressions like 割に合う (worth it) and 割に合わない (not worth it).
残業ばかりで、この仕事は正直割に合わないと思う。
With all the overtime, honestly this job doesn't feel worth it.
準備にかかった手間の割りには、売れ行きが良くなかった。
Given the effort put into the preparation, sales weren't very good.
4The assignment or allocation of people, resources, or tasks.
部屋割りは幹事が決めることになった。
It was decided that the organizer would assign the rooms.
今週の当番の割り振りを掲示板に貼った。
I posted this week's duty assignments on the bulletin board.
5In sumo, the schedule or pairing chart of bouts.
来場所の割りが発表されるのを力士たちは待っている。
The wrestlers are waiting for the next tournament's bout schedule to be announced.
6Diluting a drink with water, soda, etc., as in 水割り (whisky and water).
バーでウイスキーの水割りを頼んだ。
I ordered a whisky and water at the bar.
焼酎はお湯割りで飲むのが好きだ。
I like drinking shochu mixed with hot water.
7An abbreviation of 割引 (discount) - the rate of a price reduction.
学生証を見せれば二割になる店がある。
There are shops that give you 20% off if you show a student ID.
早割を使えば航空券がかなり安くなる。
If you use an early-bird discount, plane tickets get quite a bit cheaper.