A batch of goods was transported away for the first time (2/9), and for the second time (4/9), what fraction of this batch of goods was transported in total? How much is left undelivered?
一批货物，第一次运走了(2/9)，第二次运走(4/9)，两次一共运走这批贷物的几分之几？还剩几分之几没运走？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(2/9) + (4/9)</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>