The duration of a mathematics class is (2/3) hours, of which discussion and communication account for (1/4) of the entire class time, practical activities account for (1/6) of the entire class time, and the rest of the time students practice independently , what fraction of the whole class time did the students practice independently?
一节数学课的时间是(2/3)小时，其中讨论与交流占整节课时间的(1/4)，实践活动占整节课时间的(1/6)，其余的时间学生独立练习，学生独立练习用了整节课时间的几分之几？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/4) - (1/6)</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>