A rectangular playground is 100 meters long and 40 meters wide. How many meters does it take to run around the playground twice?
一个长方形操场，长是100米，宽40米，围着这个操场跑两圈，要跑多少米？
<gadget id="calculator">100 + 40</gadget>
<output>140</output>

<gadget id="calculator">140 * 2 * 2</gadget>
<output>560</output>

<result>560</result>