A barrel of 6 kilograms of oil is used (1/3) for the first time, and (1/4) is used for the second time. How many kilograms of oil are used for the two times?
一桶6千克的油，第一次用去(1/3)，第二次用去(1/4)，两次共用去多少千克的油？
<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">(1/3) + (1/4)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">6 * (7/12)</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>