Eight buildings are built on a piece of land with an area of 1.2 hectares, each building covers an area of 900 square meters, and the rest of the land is used for greening and roads. How many hectares is the total land area for greening and roads?
在一块面积是1.2公顷的土地上建了8幢楼房，每幢楼房占地900平方米，其余的地用于绿化和道路．绿化和道路用地面积一共是多少公顷？
<gadget id="calculator">0.09 * 8</gadget>
<output>0.72</output>

<gadget id="calculator">1.2 - 0.72</gadget>
<output>0.48</output>

<result>0.48</result>