From the cultural square to the school, Wang Jie took 5 minutes and Zhang Hua took 4 minutes. Wang Jie's speed was much slower than Zhang Hua's.
从文化广场走到学校，王杰用5分钟，张华用4分钟，王杰的速度比张华慢多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) / (1/4)</gadget>
<output>1/5 = around 0.2</output>

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