re·cur·ring dec·i·mal
noun/rɪˌkɜːrɪŋ ˈdesɪml/
/rɪˌkɜːrɪŋ ˈdesɪml/
(also repeating decimal)
(mathematics)- a decimal in which the same figure or group of figures is repeated forever, for example 3.999…
重复小数：一个小数，其中永远重复相同的图形或一组图形，例如3.999… - The recurring decimal 3.999… is also described as 3.9 recurring.
循环小数 3.999 ... 亦作 3.9 （9 循环）。
- The recurring decimal 3.999… is also described as 3.9 recurring.