The first three classes of the third grade have an average of 48 students in each class, among which there are 45 students in the first class, 51 students in the second class, and how many students are there in the third class.
三年级前3个班平均每班有学生48人，其中一班有45人，二班有51人，三班有多少人．
<gadget id="calculator">3 * 48</gadget>
<output>144</output>

<gadget id="calculator">45 + 51</gadget>
<output>96</output>

<gadget id="calculator">144 - 96</gadget>
<output>48</output>

<result>48</result>