A factory completed 75% of the plan in the first half of the month, and completed (1/2) of the plan in the second half of the month. How much is the increase in production this month?
某厂上半月完成计划的75%，下半月完成计划的(1/2)，这个月增产多少．
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) - 1</gadget>
<output>-1/2 = around -0.5</output>

<gadget id="calculator">(3/4) + (-1/2)</gadget>
<output>1/4 = around 0.25</output>

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