There is a pile of yellow sand weighing (1/2) tons on the construction site. Use up (1/4) of this pile of yellow sand in the morning, and (1/3) of this pile of yellow sand in the afternoon, what fraction of this pile of yellow sand is left?
工地有一堆黄沙重(1/2)吨．上午用去这堆黄沙的(1/4)，下午用去这堆黄沙的(1/3)，还剩下这堆黄沙的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/4) - (1/3)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>