名数是带有单位名称的数，由量数和计量单位的名称组合而成。

名数有单名数和复名数之分。其中单名数指只含有一个单位名称的名数，比如“3本”、“5千米”等；而复名数则是含有两个或两个以上的同类计量单位名称的名数，比如“3分32秒500毫秒”、“42千米195米”等。复名数可以看作是多个单名数累积而成。

注意，复名数中的计量单位必须是同类的，其余如“3千克零5米”则不能称作复名数；另外，单名数并不代表其量数一定是整数，“42.195千米”同样也是单名数。

单名数与复名数之间一般可以按照进率互相转化。对于单名数转化为复名数，首先应将单名数的量数部分进行取整并保持不变，将剩余的纯小数部分乘以适当的进率化为低级单位，使其量数变为整数。而对于复名数转化为单名数，则直接将低级单位的量数除以进率，累加在统一后的单位的量数中。

A concrete number is a number associated with the things being counted, in contrast to an abstract number which is a number as a single entity. For example, "five apples" and "half of a pie" are concrete numbers, while "five" and "one half" are abstract numbers. In mathematics the term "number" is usually taken to mean an abstract number. A denominate number is a type of concrete number with a unit of measure attached with it. For example, 5 inches is a denominate number because it has the unit inches after it.