+ (-le了) + complement of quantity + (le了)
Specifying the quantity that has been or will be added to or removed from the object as a result of the action.
Shāngdiàn bǎ diànshì de jiàgé jiàngdī-le yí bàn. 商店把电视的价格降低了一半。 Stores have lowered the price of televisions by half.
Wǒmen yídìng yào bǎ chǎnliàng tígāo-le bǎi fēn zhī èr. 我们一定要把产量提高百分之二。 We must increase the output by two percent.
Tā yǐjīng bǎ cài qiē-le yí bān le. 他已经把菜切了一半了。 He has already cut half of the vegetables up to now.