倍数表达
A is n times B. -> A是B的n倍。A=nB
A is more than n times B. -> A>nB
A is less than n times B. -> A<nB
There are A n times as many as B. -> A=nB
There are n times A as many as B. -> A=nB
e.g. There are more than twice as many employees in department A as in department B. -> A>2B
There are n times as many A as B. -> A=nB
诀窍：as等同于“等于”，然后A与B这两个对象在句子中出现的先后顺序决定了其在数学表达式中的顺序，倍数一律出现在等号的右侧（后面）。
比例表达
the ratio of A to B. -> A : B
e.g. The ratio of the number of dogs to the number of cats at the kennel (窝）is 3 to 2.
the number of dogs ÷ the number of cats = 3 : 2
A is directly proportional to B. -> A与B成正比。
A is inversely proportional to B. -> A与B成反比。
百分数表达
A is what percent of B? -> A占B的百分之几？
A is 50% more than B. -> A比B多了（B的）百分之五十。-> A=1.5B
A is what percent greater than B? -> (A-B)/B*100%
The percent increase/ decrease … -> 上涨或者下跌的百分比
