打几折,就是100减掉几十的百分数,然后off 比如:八折:20% off 八五折:at 15% discount 九七折:discount three percent 七折:discount of 30% 九折:ten per cent off 六折:make an allowance of 40%打八折应该说at twenty percent discount而不是at 80 percent discount.
上楼已经翻译的很好了