Macro Shopping Center saved an average of 50 kilowatt-hours of electricity per month last year. According to this calculation, how much electricity was saved last year.
万家乐购物中心去年平均每月节约用电50度，照这样计算，去年节约用电多少度．
<gadget id="calculator">50 * 12</gadget>
<output>600</output>

<result>600</result>