Uncle Wang inserted a bamboo pole into his fish pond. The length of the bamboo pole was 4 meters, the part inserted into the mud was 0.7 meters long, and the part exposed to the water was 1.05 meters. How deep is Uncle Wang's fish pond?
王伯伯把一根竹竿插进自己家的鱼塘里，竹竿的长度4米，插进泥里的部分长0.7米，露出水面的部分是1.05米，王伯伯家的鱼塘深为多少米？
<gadget id="calculator">4 - 1.05 - 0.7</gadget>
<output>2.25</output>

<result>2.25</result>