How many kilograms is (2/5) of 50 kilograms?
50千克的(2/5)是多少千克．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">50 * (2/5)</gadget>
<output>20</output>

<result>20</result>