The school wants to build a cuboid-shaped swimming pool with a length of 50 meters, a width of 25 meters, and a depth of 1.8 meters. The walls of the swimming pool are tiled. If 20 tiles are used per square meter, how many tiles are needed?
学校要建造一个长方体形状的游泳池，长50米，宽25米，深1.8米，游泳池的四壁用瓷砖贴，如果每平方米用瓷砖20块，共需要瓷砖多少块？
<gadget id="calculator">50 * 1.8</gadget>
<output>90</output>

<gadget id="calculator">25 * 1.8</gadget>
<output>45</output>

<gadget id="calculator">90 + 45</gadget>
<output>135</output>

<gadget id="calculator">135 * 2 * 20</gadget>
<output>5_400</output>

<result>5_400</result>