The mass of a football is equivalent to the mass of 2 volleyballs, the mass of a volleyball is equivalent to the mass of 90 table tennis balls, and the mass of a table tennis ball is about 3 grams, so how many grams is a football equivalent to?
一个足球的质量相当于2个排球的质量，1个排球质量相当于90个乒乓球质量，1个乒乓球约重3克，那么一个足球相当于多少克．
<gadget id="calculator">2 * 90 * 3</gadget>
<output>540</output>

<result>540</result>