Lay a layer of concrete with a thickness of 3 cm on the floor of an office with a length of 4 meters and a width of 3 meters. How many cubic meters of concrete are needed?
在一间长4米、宽3米的办公室地面铺一层厚3厘米的混凝土．需要多少立方米的混凝土？
<gadget id="calculator">3 / 100</gadget>
<output>3/100 = around 0.03</output>

<gadget id="calculator">4 * 3 * (3/100)</gadget>
<output>9/25 = around 0.36</output>

<result>9/25 = around 0.36</result>