Answer:
You need four squares.
On the top left square, you put the number 20 over it, and the number 30 to it's left. Put the number 600 in the square.
Next, the bottom left square. But the number 8 on the left side of the square, and put the number 160 in the square.
Now, the top right box. put the number 4 over it, and fill it with the number 120.
Last, fill the bottom right square with the number 32.