An orchard covers an area of 20 hectares, of which (1/2) is planted with apple trees, (1/4) is planted with pear trees, and the rest is planted with oranges, how many hectares are planted with oranges?
一个果园占地20公顷，其中的(1/2)种苹果树，(1/4)种梨树，剩下的地种橘子，种橘子多少公顷？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 * (1/4)</gadget>
<output>5</output>

<result>5</result>