Use a 3-meter-long bamboo pole to measure the water depth. The part above the water is 2.4 meters long. How deep is the water in meters?
用一根3米长的竹竿测水深，露出水面的部分长2.4米，请问水深多少米？
<gadget id="calculator">3 - 2.4</gadget>
<output>0.6</output>

<result>0.6</result>