A bag of flour weighs 3 kilograms and has been eaten (2/7), how many kilograms have been eaten?
一袋面粉重3千克，已经吃了(2/7)，则吃了多少千克？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">3 * (2/7)</gadget>
<output>6/7 = around 0.857143</output>

<result>6/7 = around 0.857143</result>