Put a layer of cement on a swimming pool. The swimming pool is 60 meters long, 20 meters wide, and 4 meters high. How many square meters do you need to plaster?
把一个游泳池抹一层水泥，游泳池长60米，宽20米，高4米，需要抹多少平方米？
<gadget id="calculator">60 * 20</gadget>
<output>1_200</output>

<gadget id="calculator">60 * 4</gadget>
<output>240</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<gadget id="calculator">240 + 80</gadget>
<output>320</output>

<gadget id="calculator">320 * 2</gadget>
<output>640</output>

<gadget id="calculator">1_200 + 640</gadget>
<output>1_840</output>

<result>1_840</result>