Install tiles in a cuboid reservoir with a length of 20 meters, a width of 10 meters, and a depth of 2.5 meters. The tiles are squares with a side length of 0.2 meters. How many tiles are needed in total?
在一个长20米，宽10米，深2.5米的长方体蓄水池里面贴瓷砖，瓷砖是边长为0.2米的正方形，贴完共需瓷砖多少块？
<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">20 * 2.5 * 2</gadget>
<output>100</output>

<gadget id="calculator">10 * 2.5 * 2</gadget>
<output>50</output>

<gadget id="calculator">200 + 100 + 50</gadget>
<output>350</output>

<gadget id="calculator">0.2 * 0.2</gadget>
<output>0.04</output>

<gadget id="calculator">350 / 0.04</gadget>
<output>8_750</output>

<result>8_750</result>