做簡報、寫商業報告，經常要大量使用百分比，譬如「增加／減少～％」。用英文描述百分比的增加與減少有幾個不同的方式，不難理解。難的地方在於當你真的要用的時候，你會發現自己並沒有那麼確定。花一點時間先看中文，試著用英文說一遍，然後再看英文。這些句子需要你靜下心來體會箇中的差異。
1. 產值增加了35％。The output value has increased 35%.
2. 商品零售額應增加3％。Retail sales should rise by 3%. 主要成本減少60％。The prime cost decreased by 60%.
3. 採用這種新工藝，鐵的損失量減少到20％。By using this new-process the loss of metal was reduced to 20%.
4. 今年零售額與去年相比，可望增加9％。Retail sales are expected to be nine percent higher than last year.
5. 新型機械浪費10％的能源。The new-type machine wasted 10 percent energy supplied.
6. 與去年相比，今年鋼產量增加20％。There is a 20% increase of steel as compared with last year.
7. 今年生產成本僅為去年的60％。The production cost is about 60 percent that of last year.
8. 去年本省糧食產量比1978年增加20％。The grain output of last year in this province was 20% percent up on that of 1978.
