There are 12 tons of cargo, (1/4) is transported away in the first time, and the rest (1/3) is transported away in the second time, how many tons are transported in total in the two times.
有12吨货物，第一次运走它的(1/4)，第二次运走剩下的(1/3)，两次一共运走多少吨．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

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

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

<gadget id="calculator">(1/4) + (1/4)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 * (1/2)</gadget>
<output>6</output>

<result>6</result>