To find the number of matrices

Question

Is there any formula to find the number of all possible matrices of order n × n with each entry 0 or 1 ?

Answer 1

We have 2 choices for $n^2$ entries thus for the Rule of product

$$\overbrace{2\cdot 2\cdot 2\cdot 2\cdot ...\cdot 2}^{\color{red}{n^2 \,times}}=2^{n^2}$$

Answer 2

I'd say $2^{n^2}$ for you have 2 choices for each of the $n^2$ entries