A duck weighs 3 kg, and a chicken weighs (2/3) that of the duck. How much does the chicken weigh?
一只鸭重3千克，一只鸡的重量是鸭的(2/3)，这只鸡重多少千克？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 * (2/3)</gadget>
<output>2</output>

<result>2</result>