Ummm..perhaps the instructor was mathematically challenged? Perhaps they wanted to make a 4 rectangle instead of a 4 square block? So... you got it. Cut the strips 2 1/2 wide. sew together. Cut the sewn strip 2 1/2 in wide again. Reverse one half and sew to make your 4 1/2 inch squares, to make 4 inch finished squares.
How many squares are you making?
tim in san jose