Xiao Wang inserts a 3-meter-long bamboo pole straight into the pool. The part of the bamboo pole that enters the mud is 0.5 meters, and the part that is out of the water is 0.7 meters. How many meters is the water depth?
小王把一根3米长的竹竿直插入水池，竹竿入泥部分是0.5米，露出水面部分是0.7米，水深多少米．
<gadget id="calculator">3 - 0.5 - 0.7</gadget>
<output>1.8</output>

<result>1.8</result>