How do I divide the output of a command by two, and store the result into a bash variable?

Question

Say if i wanted to do this command:

(cat file | wc -l)/2

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

I know its simply not the case of

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

so how would i do it?

Answer 1

middle=$((`wc -l < file` / 2))

Answer 2

middle=$((`wc -l file | awk '{print $1}'`/2))