In a piece of land, (5/9) is used for growing cabbage, (1/7) is used for growing radish, and the rest is used for growing green vegetables. How much of this land is used for growing vegetables?
一块地，种白菜用去它的(5/9)，种萝卜用去它的(1/7)，其余的种青菜．种青菜用去这块地的几分之几？
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

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

<gadget id="calculator">(5/9) + (1/7)</gadget>
<output>44/63 = around 0.698413</output>

<gadget id="calculator">1 - (44/63)</gadget>
<output>19/63 = around 0.301587</output>

<result>19/63 = around 0.301587</result>