An apple is 1/4 heavier than an orange, and an orange is lighter than an apple by how much.
苹果比橘子重1/4，橘子比苹果轻多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(1/4) / (5/4)</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>