Divide a mooncake into 5 parts on average, 4 of which is the size of the mooncake
把一个月饼平均分成5份，其中的4份是这个月饼的多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<result>4/5 = around 0.8</result>