The store shipped in a batch of schoolbags, a total of 500, after selling (2/5), how many are left.
商店运进一批书包，共500个，卖出(2/5)后，还剩多少个．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">500 * (2/5)</gadget>
<output>200</output>

<gadget id="calculator">500 - 200</gadget>
<output>300</output>

<result>300</result>