In 1:4, the former term is enlarged by 4 times, and the latter term is reduced by 2 times. At this time, the ratio is how many times the original ratio.
1：4的前项扩大4倍，后项缩小2倍，这时的比值是原来比值的多少倍．
<gadget id="calculator">1 * 4</gadget>
<output>4</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

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

<gadget id="calculator">4 / 2 / (1/4)</gadget>
<output>8</output>

<result>8</result>