A piece of land, of which (1/4) is planted with corn, (2/5) is planted with sorghum, and the rest is planted with wheat, what percentage of the land is wheat?
一块地，其中(1/4)种玉米，(2/5)种高粱，剩下的种小麦，小麦地占这块地的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<result>7/20 = around 0.35</result>