The area of an experimental field is (2/3) hectares, of which (1/5) is used to grow buckwheat, (3/10) is used to grow millet, and the rest is grown to grow sesame. What percentage of the land is planted with sesame seeds?
一块试验田面积是(2/3)公顷，其中(1/5)用来种荞麦，(3/10)用来种小米，其余的种芝麻．种芝麻的面积占这块地的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (1/5) - (3/10)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>