There are 200 kg of pears, 80 kg are sold, how many are left
有200千克梨，卖出了80千克，还剩下多少
<gadget id="calculator">80 / 200</gadget>
<output>2/5 = around 0.4</output>

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

<result>3/5 = around 0.6</result>