There are 120 students in the sixth grade, and 75% of them have reached the national physical exercise standards. How many students have not reached the national physical exercise standards?
六年级有120名同学，其中75%的同学达到了国家体育锻炼标准，还有多少名同学没有达到国家体育锻炼标准？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">120 * (1/4)</gadget>
<output>30</output>

<result>30</result>