Answer
TRUE
Work Step by Step
The determinate for a square matrix for $m$ columns anfd $n$ rows is defined as:
$det(A)= \begin{vmatrix}p&q\\r&s\end{vmatrix}=ps-rq$
Counter Example: $det(A)= \begin{vmatrix}1&2\\3&4\end{vmatrix}=(1)(4)-(2)(3)=4-6=-2$
Therefore, the given statement is true that $det(A)$ is a number , not a square matrix.