There is a bag of rice, the first time I ate it (2/5), and the second time I ate the rest (2/3), how much of this bag of rice did the second time eat.
有一袋大米，第一次吃了它的(2/5)，第二次吃了余下的(2/3)，第二次吃的占这袋大米的多少．
<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">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(3/5) * (2/3)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>