A swimming pool with a length of 30 meters, a width of 15 meters and a depth of 2 meters is to be tiled. The tiles are squares with a side length of 3 decimeters. How many tiles are needed to finish the swimming pool?
在一个长30米，宽15米，深2米的游泳池里面贴瓷砖，瓷砖是边长为3分米的正方形，贴完这个游泳池共需瓷砖多少块？
<gadget id="calculator">30 * 15</gadget>
<output>450</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">60 + 30</gadget>
<output>90</output>

<gadget id="calculator">90 * 2</gadget>
<output>180</output>

<gadget id="calculator">450 + 180</gadget>
<output>630</output>

<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">100 / 9</gadget>
<output>100/9 = around 11.111111</output>

<gadget id="calculator">630 * (100/9)</gadget>
<output>7_000</output>

<result>7_000</result>