Squares?

There are four squares on each side as well as the whole big square, which makes 8+2=10. Then, 8x4=32. Then, there are 3 bigger squares on each rectangular side, which makes 3x4=12. 32+10+12=54. This is your answer.

There will be $4$ rectangles and $2$ squares. So in total, there will be $(4 \times 8) + (2 \times 4) = 40$ mini squares. However, there are also larger squares. Because each rectangle is $(2 x 4)$ (because the only other option is $(8 x 1)$ , which would not be big enough for a $(2 x 2)$ square), each rectangle has $3$ larger squares, and because each square is $(2 x 2)$ , each square has $1$ larger squares. In total, that is $40 + (3 \times 4) + (2 \times 1) = 54$ .