piece of grass is 40 meters long and 20 meters wide. Xiao Ming walked 2 times along the edge of the grass. How many meters did he walk in total?
一块长40米，宽20米的草地，小明沿着草地的边走了2圈，他一共走了多少米？
<gadget id="calculator">40 + 20</gadget>
<output>60</output>

<gadget id="calculator">60 * 2 * 2</gadget>
<output>240</output>

<result>240</result>