要看具体情况：表示准确数值时候,不要,比如300,500.表示大概的数量时候就要复数,但前面不加具体的数字,参考下面：
hundred
(after a or one or an indication of quantity 用於a、 one或含有数量意义的词之后) 100; one more than ninety-nine 100,一百（个）:one,two,three,etc hundred 一百、 二百、 三百 * a few hundred 几百 * There were a/one hundred (people) in the room.房间里有一百人.* I could give you a hundred reasons for not going.我可以给你说出一百个不去的理由.* This antique is worth several hundred pounds.这件古物值几百镑.* If I've said it once,I've said it a hundred times.这件事我不但说过,而且已经说过上百次了.* He's a hundred (years old) today.他今天一百岁了.=>App 4 见附录4.
> hundred n (after a or one,a number or an indication of quantity 用於a、 one、 数词或含有数量意义的词之后) the number 100 *100; 一百:How many hundreds are there in a thousand?一千里有多少个一百?* Her coat cost hundreds (of pounds).她的大衣值好几百（镑）.* There are hundreds (of people) (ie very many) who need new housing.有许许多多人需要新的住房.* The cake was decorated with a large (one) hundred.这块蛋糕上面装饰着一个很大的‘（一）百’字样.