bathroom is 3 meters long, 2 meters wide, and 2.5 meters high, and tiles with a size of 200mm*100mm are pasted on the four walls and the floor of the bathroom. How many tiles are needed at least?
一个浴室长3米，宽2米，高2.5米，在浴室的四壁和地面贴上规格是200mm*100mm的瓷砖，至少需要瓷砖多少块？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">3 * 2.5</gadget>
<output>7.5</output>

<gadget id="calculator">2 * 2.5</gadget>
<output>5</output>

<gadget id="calculator">6 + 7.5 + 5</gadget>
<output>18.5</output>

<gadget id="calculator">18.5 * 2</gadget>
<output>37</output>

<gadget id="calculator">37 - 6</gadget>
<output>31</output>

<gadget id="calculator">0.2 * 0.1</gadget>
<output>0.02</output>

<gadget id="calculator">31 / 0.02</gadget>
<output>1_550</output>

<result>1_550</result>