Twice. Dividing by ten will move the decimal point one place to the left. Rather than dividing by ten twice, you can divide by 100 once.
Answer:
5 parts are shaded and 4 parts are white so:
There are 9 parts all together.
We can then form ratio's of the white areas and the shaded areas:
White Area Ratio =

Shaded Area Ratio =

Let the area of sqaure be equated to x, which means let the entire area of the square equal to x:
x = Area of whole square
Now we can form an equation :

So now we just need to solve for x:


The area of the square is:
