In order to celebrate Christmas, Class 6 and Class 2 have to make 180 greeting cards, which have already been done (5/6), how many cards are still left?
为了庆祝圣诞节，六2班要做180张贺卡，已经做了(5/6)，还有多少张没有做？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">180 * (1/6)</gadget>
<output>30</output>

<result>30</result>