A real estate in Shaoyang originally planned to sell it at an average price of 4,000 yuan per square meter. The State Council issued a new policy on real estate, and most home buyers waited and watched. In order to speed up capital turnover, the real estate developer lowered the price and decided to start selling at an average price of 3,600 yuan per square meter. By what percentage was the average price per square meter lowered at the opening?
邵阳市某楼盘原计划以每平方米4000元的均价对外销售．国务院有关房地产的新政策出台，大部分购房者持币观望．为了加快资金周转，房地产开发商对价格进行了下调，决定以每平方米3600元的均价开盘销售．开盘时每平方米的均价下调了百分之几？
<gadget id="calculator">4_000 - 3_600</gadget>
<output>400</output>

<gadget id="calculator">400 / 4_000</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(1/10) * 1</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>