Xiaoling participates in the math competition, the total number of questions in the whole volume is 18, and Xiaoling only does the correct number of questions (4/9). How many questions did Xiao Ling do wrong?
小玲参加数学竞赛，全卷总题数是18题，小玲只做对总题数的(4/9)．小玲做错了多少题？
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 - (4/9)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">18 * (5/9)</gadget>
<output>10</output>

<result>10</result>