What is the area of a rectangular piece of plastic paper with a length of 3 decimeters and a width of 20 centimeters?
一块长3分米，宽是20厘米的长方形塑料纸，它的面积是多少？
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">30 * 20</gadget>
<output>600</output>

<result>600</result>