The three members of Zhang Hua's family eat an average of 15 kilograms of grain per person per month. Then, how many kilograms does their family of three eat in a year?
张华家三口人，平均每人每月要吃15千克粮食，那么，他们一家三口1年要吃多少千克．
<gadget id="calculator">15 * 3 * 12</gadget>
<output>540</output>

<result>540</result>