There are 153 boys and 135 girls in the fourth grade of Jinshan Primary School, with an average of 48 students in a class. How many classes are there in the fourth grade?
金山小学四年级有男生153人，女生135人，平均48人一个班，四年级一共有多少个班？
<gadget id="calculator">153 + 135</gadget>
<output>288</output>

<gadget id="calculator">288 / 48</gadget>
<output>6</output>

<result>6</result>