Xiao Ming's living room is 5 meters long and 4 meters wide. The floor is covered with square tiles with a side length of 5 decimeters, how many tiles are needed?
小明家的客厅长5米，宽4米．地面上铺有边长为5分米的正方形地砖，需要多少块地砖？
<gadget id="calculator">5 * 4 * 100</gadget>
<output>2_000</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">2_000 / 25</gadget>
<output>80</output>

<result>80</result>