Xiangyang Supermarket has imported (5/9) tons of Chinese cabbage and sold (1/9) tons, how many tons are left unsold?
向阳超市运进(5/9)吨大白菜，已经卖出(1/9)吨，还有多少吨没卖？
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(5/9) - (1/9)</gadget>
<output>4/9 = around 0.444444</output>

<result>4/9 = around 0.444444</result>