The master worker is going to lay bricks on the street square with a length of 40 meters and a width of 30 meters. If the side length of the square bricks is 20 decimeters, how many bricks are needed?
工人师傅准备给长为40米，宽为30米的街心广场铺上方砖．如果方砖的边长是20分米，那么需要多少块？
<gadget id="calculator">40 * 20</gadget>
<output>800</output>

<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">800 / 4</gadget>
<output>200</output>

<result>200</result>