Liangliang’s house uses an average of 45 kWh of electricity per month. According to this calculation, how many kWh of electricity will be used in a year.
亮亮家平均每月用电45千瓦时，照这样计算，一年要用电多少千瓦时．
<gadget id="calculator">45 * 12</gadget>
<output>540</output>

<result>540</result>