Let’s find the area of the rectangular cake and the square pieces.
I’m going to turn the fractions into decimals since it’s easier for me.
13.5•9
121.5
Now find the area of the square pieces.
2.25•2.25
5.0625
Now divide the area of the cake by the pieces to find how many can fit.
121.5/5.0625
24
So, 24 square pieces can be cut out of the rectangular cake.