Cut off a square with a side length of 5 cm from the four corners of a square cardboard with a side length of 30 cm to make a carton without a cover. What is the volume of this carton in cm**3? (The thickness of the cardboard is not counted)
把一个边长30cm的正方形硬纸板的四个角各剪去一个边长5cm的正方形，做成一个无盖的纸盒．这个纸盒容积是多少cm**3？(纸板的厚度不计)
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

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

<gadget id="calculator">20 * 20 * 5</gadget>
<output>2_000</output>

<result>2_000</result>