Xiao Ling's study room is 5 meters long and 4 meters wide, and the floor is paved with square bricks with a side length of 2 decimeters. How many square bricks are needed in total?
小玲家的书房长5米，宽4米，在地面上铺边长2分米的方砖，一共需要多少块方砖？
<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">4 / (1/25)</gadget>
<output>100</output>

<gadget id="calculator">5 * 100</gadget>
<output>500</output>

<result>500</result>