There are 50 people in Class 1, 6, 90% of them reach the standard in physical education, and how many people fail to meet the standard.
六1班有50人，体育成绩达标的占90%，不达标的有多少人．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">50 * (1/10)</gadget>
<output>5</output>

<result>5</result>