• 割合わりあい — ratio / proportion
• 割引わりびき — discount
• 割わる — to divide / split
• 分割ぶんかつ — division / partition
• 割当わりあて — allocation / assignment
• 割わり算ざん — division (math)
• 割わり箸ばし — disposable chopsticks

割 combines the radical 刂 (sword/knife, symbolizing cutting) with 害 (as the phonetic element). The character depicts the act of cutting or breaking apart.

Its usage extends from physical splitting to abstract meanings like percentages (割合) and division in mathematics (割り算).

割引わりびきが 使つかえます。
You can use a discount.

割合わりあいに 男おとこの 人ひとが 多おおいです。
There is a high ratio of men.