如何将命令的输出除以二，并将结果存储到bash变量中?

请问是否要执行以下命令:

Say if i wanted to do this command:

(cat file | wc -l)/2

并将其存储在诸如Middle这样的变量中，我该怎么办?

and store it in a variable such as middle, how would i do it?

我知道不是

$middle=$(cat file | wc -l)/2

那我该怎么办?