循环小数3.999...亦作3.9循环。

The recurring decimal 3.999... is also described as 3.9 recurring.

我对你的思念就是一个循环小数。

I miss you is a repeating decimals?

通过研究、猜测，提出了循环小数特征值的概念，给出了一系列重要命题。

This paper, by studying and guessing, has advanced the concept of the characteristic value of the prime recurring decimal, and given a series of important propositions.