It takes 320 pieces to pave a floor with square bricks with an area of 9 square decimeters. If the floor is paved with square bricks with a side length of 4 decimeters, how many bricks are needed?
用面积是9平方分米的方砖铺一块地，需320块，如果改用边长4分米的方砖铺地，需多少块砖？
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">320 / 16</gadget>
<output>20</output>

<gadget id="calculator">9 * 20</gadget>
<output>180</output>

<result>180</result>