A glass of water and the cup weigh (5/9) kilograms, and the cup weighs (1/9) kilograms. How many kilograms does the water in the cup weigh?
一杯水连杯子共重(5/9)千克，杯子重(1/9)千克，这个水杯里的水重多少千克？
<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>