A rectangular iron sheet with a length of 50 cm and a width of 30 cm, cut a small square with a side length of 5 cm from its four corners, and then fold up the four sides to make a rectangular box without a cover. What is the volume in liters.
一张长50厘米，宽30厘米的长方形铁皮，在它的四个角上都剪去一块边长5厘米的小正方形，再把四边向上折起，做成一个无盖的长方体盒子，这个盒子的容积是多少升．
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<gadget id="calculator">30 - 10</gadget>
<output>20</output>

<gadget id="calculator">5 / 1_000</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">40 * 20 * (1/200)</gadget>
<output>4</output>

<result>4</result>