Xiao Ming ran twice around a rectangular playground with a length of 50 meters and a width of 30 meters. How many meters did he run in total?
小明围着一个长50米，宽30米的长方形操场跑了两圈，他一共跑了多少米？
<gadget id="calculator">50 + 30</gadget>
<output>80</output>

<gadget id="calculator">80 * 2 * 2</gadget>
<output>320</output>

<result>320</result>