In a certain grade, there are 51 students in class one, 54 students in class two, and 107 students in class three and four. How many students are there on average in each class? what is the correct formula
某年级一班有学生51人，二班有学生54人，三、四班一共有学生107人，平均每个班有学生多少人？正确的算式是多少
<gadget id="calculator">51 + 54 + 107</gadget>
<output>212</output>

<gadget id="calculator">212 / 4</gadget>
<output>53</output>

<result>53</result>