The price of a commodity is first increased by 20%, and then reduced to 80%, how much is the current price lower than the original price?
一种商品的价格先提高20%，再降低到80%，现在的价格与原价相比降低了多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(6/5) * (4/5)</gadget>
<output>24/25 = around 0.96</output>

<gadget id="calculator">1 - (24/25)</gadget>
<output>1/25 = around 0.04</output>

<result>1/25 = around 0.04</result>