The area of a classroom is 86.4 square meters, and the floor is paved with square tiles with a side length of 40 cm. How many tiles of this kind are needed?
一间教室的面积是86.4平方米，用边长40厘米的正方形瓷砖铺地，共需要这种瓷砖多少块？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * (2/5)</gadget>
<output>4/25 = around 0.16</output>

<gadget id="calculator">86.4 / (4/25)</gadget>
<output>540</output>

<result>540</result>