When Uncle Wang drove to work, his speed was 20% lower than usual, so how much longer was the time on the road than usual?
王叔叔开车上班时，车速比平时降低了20%，那么在路上的时间比平时增加了多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">5 * (4/5)</gadget>
<output>4</output>

<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/4) - 1</gadget>
<output>1/4 = around 0.25</output>

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

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