小数点用英语怎么说

小数点用英语说作"decimal point"。它的来源可以追溯到古罗马的一位数学家兼天文学家卡普兰（Ptolemy），他在公元前2世纪时在其著作《地理》（Geography）中第一次使用了小数点。

一些英文例句如下：

The decimal point separates the whole number part from the fractional part of a number.

In the number 3.14, the decimal point indicates that the number is a combination of three whole numbers and 14 hundredths.

You can use the decimal point to make large numbers easier to read and understand. For example, the number 100,000 can be written as 100.000, which is easier to read and understand.