It took Xiaoling 50 minutes to do the homework for the three subjects, 20 minutes for the Chinese homework, (1/4) hour for the English homework, how many hours did it take for the math homework?
小玲做三门功课的作业一共用了50分钟，做语文作业用了20分钟，做英语作业用了(1/4)小时，做数学作业用了多少小时？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

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

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

<gadget id="calculator">(5/6) - (1/3) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>