Xiao Ming's walking time from home to school is reduced from 10 minutes to 8 minutes, how much does his speed increase
小明从家到学校行走的时间由原来的10分钟减少到8分钟，他的速度加快了多少
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/8) - (1/10)</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">(1/40) / (1/10)</gadget>
<output>1/4 = around 0.25</output>

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