Fangfang has done 24 math problems, 18 of which have been completed, how much of all the problems still need to be completed
芳芳做24道数学题，已完成了18道，还需完成全部题目的多少
<gadget id="calculator">24 - 18</gadget>
<output>6</output>

<gadget id="calculator">6 / 24</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>