A bag of rice is 50 kilograms. After eating (2/5) in the first week, how many kilograms are left?
一袋大米50千克，第一周吃了(2/5)，还剩多少千克．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">50 * (3/5)</gadget>
<output>30</output>

<result>30</result>