(7/9) of a piece of green land is used for planting grass, and (2/9) is used for planting trees. What fraction of the land is used for planting trees compared to the ground for planting grass?
一块绿化地的(7/9)用于种草，(2/9)用于植树，植树的地面比种草的地面少这块地的几分之几？
<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(7/9) - (2/9)</gadget>
<output>5/9 = around 0.555556</output>

<result>5/9 = around 0.555556</result>