（一）a is n times as small （light，slow，…）as b.
a is n times smaller （lighter， slower，…) than b.
以上两句均应译为：a的大小（重量，速度，……）是b的1/n[或a比b小（轻，慢，……）（n-1）/n]。 e.g. The hydrogen atom is near1y l6 times as light as the oxygen atom. 氢原子的重量约为氧原子的1/16（即比氧原子约轻15/16）。 e.g. This sort of membrane is twice thinner than ordinary paper. 这种薄膜比普通纸张要薄一半（即是普通纸厚度的1/2）。
注：当相比的对象b很明显时，than/as b常被省去。
（二）decrease n times/n--fold
decrease by n times
decrease by a factor of n
以上三式均译为：减少到1/n[或：减少(n-1)/n]。
decrease常被reduce，shorten，go／slow down等词替代。 e.g. Switching time of the new-type transistor is shortened 3 times. 新型晶体管的开关时间缩短了1/3（即缩短到2/3）。 e.g. When the voltage is stepped up by ten times, the strength of the current is stepped down by ten times. 电压升高9倍，电流强度便降低9/10（即90％）。 e.g. The equipment reduced the error probability by a factor of 5. 该设备误差概率降低了4/5。
（三）there is a n-fold decrease/reduction… 应译为：减至1/n [或：减少（n一1）/n]。
这个句型还有其它一些形式， e.g. A rapid decrease by a factor of 7 was observed． 发现迅速减少到1/7。 e.g. The principal advantage of the products is a two-fold reduction in weight. 这些产品的主要优点是重量减轻了1/2。
