In the art exhibition, the first grade exhibited 158 pieces of students' works, and the number of works of the sixth grade was three times that of the first grade.
在美术作品展上，一年级展示了158张学生作品，六年级的作品数是一年级的3倍，一年级比六年级少多少张作品？
<gadget id="calculator">158 * 3</gadget>
<output>474</output>

<gadget id="calculator">474 - 158</gadget>
<output>316</output>

<result>316</result>