Pingping and grandma set off from home to the supermarket one after another. Pingping walked for 4 minutes, and grandma walked for 5 minutes. Pingping's speed was much faster than grandma's.
平平与奶奶先后从家出发到超市，平平走了4分钟，奶奶走了5分钟，平平的速度比奶奶快多少．
<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>