From the school to the supermarket, it takes Zhang Hua 4 minutes and Li Qiang 5 minutes. Zhang Hua is much faster than Li Qiang.
从学校到超市，张华需4分钟，李强需5分钟，张华的速度比李强快多少．
<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) / (1/5)</gadget>
<output>1/4 = around 0.25</output>

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