How many planks are needed to lay square wooden boards with a side length of 2 decimeters on the floor of a basketball gymnasium with a length of 40 meters and a width of 10 meters?
在一块长40米，宽10米的篮球馆地面上，铺上边长2分米的正方形木板，需要多少块木板？
<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * (1/5)</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">10 / (1/25)</gadget>
<output>250</output>

<gadget id="calculator">40 * 250</gadget>
<output>10_000</output>

<result>10_000</result>