A rectangular lawn is 7 meters long and 3 meters wide. Xiaohua walked around the lawn for 2 weeks. How many meters did he walk in total?
一个长方形草坪，长7米，宽3米，小华沿着草坪周围走2周，一共走了多少米？
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">10 * 2 * 2</gadget>
<output>40</output>

<result>40</result>