A fish tank with a length of 50 cm, a width of 30 cm, and a height of 40 cm contains 37.5 L of water. After putting a few goldfish, the water level rises by 2 cm. What is the volume of these goldfish in cubic decimeters?
长50cm，宽30cm，高40cm的鱼缸中盛有37.5L水，放入几条金鱼后，水面上升了2cm．这几条金鱼的体积是多少立方分米？
<gadget id="calculator">2 / 1_000</gadget>
<output>1/500 = around 0.002</output>

<gadget id="calculator">50 * 30 * (1/500)</gadget>
<output>3</output>

<result>3</result>