The price of a vegetable in the second week of January is 20% more expensive than the first week, and the third week is 20% cheaper than the second week. Compared with the first week, is the price of this vegetable more expensive or cheaper? up? What is the magnitude of the change?
一种蔬菜价格1月份第二周比第一周贵了两成，第三周又比第二周便宜了两成，第三周和第一周相比，这种蔬菜价格是贵了还是便宜了？变化幅度是多少？
<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">1 - (1/5)</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>