From Small to Large

There are $5$ squares size $12$ visible immediately,

plus four half squares the same size (making $2$ more squares),

and finally four quarter squares also the same size (making $1$ more).

So there are total of $5+2+1=8$ squares size $12$ giving us $8\times12=\boxed{96}$ .

First there are 5 visibly squares each with area of 12 - $5 \times 12 = 60$ ,

then there are four $\frac{1}{2}$ (middle up, down, left, right) - $4 \times 6 = 2 \times 12 = 24$

and $\frac{1}{4}$ (corners) - $4 \times 3 = 12$ .

60 + 24 + 12 = 96