workshop produces 80 machine tools in the first half of the year, and increases to 120 in the second half of the year. What percentage is the increase? What is the correct column
某车间上半年生产80台机床，下半年增加到120台，增加了百分之几？正确的列式是多少
<gadget id="calculator">120 - 80</gadget>
<output>40</output>

<gadget id="calculator">40 / 80</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>