In a kitchen with a length of 40 decimeters and a width of 30 decimeters, it is necessary to lay square floor tiles on the floor. How many decimeters of square tiles should be selected so that the floor can be laid neatly and economically?
在一间长40分米，宽30分米的厨房地面要铺正方形地砖，需选边长为多少分米的方砖，才能铺得既整齐又节约？
<gadget id="calculator">2 * 5</gadget>
<output>10</output>

<result>10</result>