1. You do the math.
你自已算算看吧。
Math 本身是「數學」的意思,而 do the math 則是一個慣用法,意思就是請別人自己算算看。假設今天有一個老美問我,"How long have you been waiting at the airport?" (你在機場等多久了?),這時我的回答可以是,"I came here at 9 am, and now it's 3 pm. You do the math." (我早上九點就來了,而現在已經是下午三點了,你自己算算看有多久吧!) 所以由此觀之,這個 "You do the math." 通常是在引出一連串的數據數據之后,放在句尾,請人家自己完成數學的計算部份。再舉一例,比方說老美問我,"Do you know how far it is between the sun and the earth?" (你知道從太陽到地球有多遠嗎?) 這時我可以回答說,"The speed of light is 186,000 miles per second; it takes 8 1/2 minutes for the light to travel from the sun to the earth. You do the math." (光速是每秒 186,000 英哩,而光從太陽到地球需要八分半鐘,你自己算算看吧!)
"You do the math." 這樣的用法在日常生活當中十分常見,舉凡加減乘除之類跟數學有關的運算,你都可以用 "You do the math." 來表示我知道答案但我懶得算,想知道答案就請自己算算看。當然如引言所述,你也可以用 "You do the calculation." 但這樣的用法遠不及 "You do the math." 來得普遍。