Use square bricks with a side length of 40cm to pave a section of sidewalk with a length of 20m and a width of 16m. How many square bricks should be used at least?
用边长是40cm的正方形方砖铺一段长20m、宽16m的人行路面，至少要用多少块这样的方砖？
<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>