The floor of Xiao Ming's bedroom is a square with a side length of 3m. The floor is paved with isosceles triangle tiles with a base of 4dm and a height of 2.5dm. How many tiles are needed?
小明的卧室的地面是边长为3m的正方形，用底是4dm，高是2.5dm的等腰三角形瓷砖铺地，需要多少块瓷砖？
<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2.5 / 10</gadget>
<output>0.25</output>

<gadget id="calculator">0.25 / 2</gadget>
<output>0.125</output>

<gadget id="calculator">(2/5) * 0.125</gadget>
<output>0.05</output>

<gadget id="calculator">3 / 0.05</gadget>
<output>60</output>

<gadget id="calculator">3 * 60</gadget>
<output>180</output>

<result>180</result>