There are 35 students in class 6 and 2, and 80% of the students pass a math test, so how many people fail?
六2班有学生35人，在一次数学测验中有80%的学生及格，那么不及格有多少人．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">35 * (1/5)</gadget>
<output>7</output>

<result>7</result>