To make a cube glass fish tank without a cover, the side length is 3 decimeters, at least how many square meters of glass is needed?
做一个没盖的正方体玻璃鱼缸，棱长是3分米，至少需要玻璃多少平方米？
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">3 * 3 * (1/20)</gadget>
<output>9/20 = around 0.45</output>

<result>9/20 = around 0.45</result>