There are (7/9) tons of wheat in the granary, (2/3) tons are shipped out, and (5/18) tons are shipped in, how many tons of wheat are there in the warehouse now?
粮仓里有小麦(7/9)吨，运走了(2/3)吨，又运进来(5/18)吨，现在仓库里的小麦有多少吨？
<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(7/9) - (2/3)</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">5 / 18</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">(1/9) + (5/18)</gadget>
<output>7/18 = around 0.388889</output>

<result>7/18 = around 0.388889</result>