There are a total of 256 students in the fourth grade. Some students are selected to rehearse group exercises. There are 16 students in each row, and there are 8 rows. How many students are not selected?
四年级一共有256名同学，选出一些同学排练团体操，每排16名同学，排了8排，还有多少名同学没选上？
<gadget id="calculator">16 * 8</gadget>
<output>128</output>

<gadget id="calculator">256 - 128</gadget>
<output>128</output>

<result>128</result>