Wang Fei's weight is 42 kg, Li Li's weight is Wang Fei's (6/7), Zhao Gang is heavier than Li Li (2/9), how many kilograms is Zhao Gang heavier than Li Li?
王飞的体重是42千克，李丽的体重是王飞的(6/7)，赵刚比李丽重(2/9)，赵刚比李丽重多少千克？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">42 * (6/7) * (2/9)</gadget>
<output>8</output>

<result>8</result>