舍入以特定方式加倍

Question

我想知道某种包装中是否存在这种类型的数字舍入。

Ex:
if a number is 3333.[0-4] it should become 3330
if a number is 3333.[5-9] it should become 3335
if a number is 3337.[0-4] it should become 3335
if a number is 3337.[5-9] it should become 3340

感谢您的回答。