One day, both Avanti and Master Bai found some gold coins, but the greedy Master Bai proposed an exchange method: the two exchanged their respective gold coins twice, and each time they used all the gold coins of Avanti. Half of it is exchanged for the gold coins of Lord Bayi (1/5). Avanti agreed to Master Bayi's request. After the first exchange, Mr. Bayi had 450 gold coins left, and after the second exchange, Avanti had 150 gold coins left. Please do the math, has Avanti's gold coins increased or decreased compared to the original? How many coins did he increase (or decrease)?
一天，阿凡提和巴依老爷都找到了一些金币，可是贪得无厌的巴依老爷提出了一个交换的方法：两人把各自的金币进行两次交换，且每次都用阿凡提全部金币的一半换巴依老爷金币的(1/5)．阿凡提答应了巴依老爷的要求．第一次交换后巴依老爷剩下金币450枚，第二次交换后阿凡提剩下金币150枚．请算一算，阿凡提的金币比原来是增加了还是减少了？他增加(或减少)了多少枚金币？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">450 * (1/5)</gadget>
<output>90</output>

<gadget id="calculator">150 - 90</gadget>
<output>60</output>

<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<gadget id="calculator">450 - 120</gadget>
<output>330</output>

<gadget id="calculator">1 - (1/5) - (1/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">330 / (3/5)</gadget>
<output>550</output>

<gadget id="calculator">550 * (1/5)</gadget>
<output>110</output>

<gadget id="calculator">120 - 110</gadget>
<output>10</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<gadget id="calculator">150 - 20</gadget>
<output>130</output>

<result>130</result>