To lay floor tiles on the floor of an auditorium with a length of 20 meters and a width of 16 meters, if a square floor tile with a side length of 40 cm is used, how many tiles are needed at least?
给一间长20米，宽16米的礼堂地面铺地面砖，如果选用边长为40厘米的正方形地砖铺，至少需要多少块？
<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">16 / (4/25)</gadget>
<output>100</output>

<gadget id="calculator">20 * 100</gadget>
<output>2_000</output>

<result>2_000</result>