cuboid swimming pool is 20 meters long, 10 meters wide, and 2 meters deep. The walls and bottom are plastered with cement. How many square meters is the area to be plastered with cement?
一个长方体游泳池，长20米，宽10米，池深2米，在四壁和底面抹水泥，求抹水泥的面积是多少平方米？
<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

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

<gadget id="calculator">200 + 40 + 20</gadget>
<output>260</output>

<gadget id="calculator">260 * 2</gadget>
<output>520</output>

<gadget id="calculator">520 - 200</gadget>
<output>320</output>

<result>320</result>