From school to the bookstore, it took Xiao Ming 40 minutes and Xiao Hua 50 minutes. How much faster is Xiao Ming than Xiao Hua?
从学校到书店，小明用了40分钟，小华用了50分钟，小明比小华的速度快多少．
<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/40) - (1/50)</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">(1/200) / (1/50)</gadget>
<output>1/4 = around 0.25</output>

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