作为一个经验法则，煮饭时每100克大米通常对应200毫升水。

As ___a ___rule ___of ___thumb, you should use 200ml of water for every 100g of rice when cooking.

个人理财的一个好用经验法则是每月至少存下收入的20%。

A good ___a ___rule ___of ___thumb for personal finance is to save at least 20% of your monthly income.

一个粗略估算时很有用的经验法则是假设每人会吃掉大约200克意大利面。

A useful ___a ___rule ___of ___thumb for a rough estimate is to assume one person will eat about 200g of pasta.