It is planned to use (6/7) of a piece of land for planting grass and (1/7) for planting trees. What percentage of the land is less for planting trees than for planting grass?
计划将一块地的(6/7)用于种草，(1/7)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">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(6/7) - (1/7)</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>