rectangular piece of cardboard, 30 cm long and 20 cm wide. Cut off a square with a side length of 5 cm at its four corners to make a cuboid box without a cover. What is the volume of this box in milliliters?
一块长方形纸板，长30厘米，宽20厘米．在它的四个角分别切掉边长是5厘米的正方形，做成一个无盖的长方体盒子．这个盒子的容积是多少毫升？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

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

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

<gadget id="calculator">20 * 10 * 5</gadget>
<output>1_000</output>

<result>1_000</result>