-A colored ribbon is (7/9) meters long, (5/12) is used for the first time, and (1/4) is used for the second time, what fraction of it is left?
-条彩带长(7/9)米，第一次用去它的(5/12)，第二次用去它的(1/4)，还剩它的几分之几？
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

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

<gadget id="calculator">(5/12) + (1/4)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>