A rope is (4/5) decimeters long, and (2/9) of it is used up for the first time, how many decimeters are left after using it (1/2) of this rope?
一根绳子长(4/5)分米，第一次用去它的(2/9)，再用去多少分米后剩下的正好是这根绳子的(1/2)？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>