The classroom is 8 meters long and 5 meters wide. If you use triangular tiles with a base of 5 decimeters and a height of 4 decimeters, how many such tiles are needed?
教室长为8米，宽5米，如果用底为5分米，高4分米的三角形瓷砖来铺，共需多少块这样的瓷砖？
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 / 10</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 2</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/2) * (1/5)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">5 / (1/10)</gadget>
<output>50</output>

<gadget id="calculator">8 * 50</gadget>
<output>400</output>

<result>400</result>