Daar is 16 enkel vierkante; 9 vierkante gemaak van 4 enkel vierkante; 4 vierkante gemaak van 9 enkel vierkante en 1 vierkant gemaak van 16 enkel vierkante.
There are 16 single squares, 9 squares made by 4 single squares, 4 squares made by 9 single squares and 1 square made by 16 single squares.