In a glass tank with a length of 25 cm and a width of 20 cm, there is a cube iron block with a side length of 10 cm. At this time, the water depth is 15 cm. If the iron block is taken out of the tank, what is the depth of the water in the tank?
在长是25厘米，宽是20厘米的玻璃缸中，有一个棱长是10厘米的正方体铁块，这时水深是15厘米，若将铁块从缸中取出，缸中水深是多少厘米？
<gadget id="calculator">25 * 20 * 15</gadget>
<output>7_500</output>

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

<gadget id="calculator">7_500 - 1_000</gadget>
<output>6_500</output>

<gadget id="calculator">25 * 20</gadget>
<output>500</output>

<gadget id="calculator">6_500 / 500</gadget>
<output>13</output>

<result>13</result>