Apple trees have fewer trees than pear trees (1/5), and pear trees have more trees than apple trees
苹果树的棵树比梨树少(1/5)，梨树的棵树就比苹果树的棵树多多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>