There are 3 classes in the fourth grade of urban primary school, with 45 students in each class; there are 4 classes in the fifth grade, with 48 students in each class. How many people are there in the fourth and fifth grades?
城中小学四年级有3个班，每班45人；五年级有4个班，每班48人．四、五年级一共有多少人？
<gadget id="calculator">45 * 3</gadget>
<output>135</output>

<gadget id="calculator">48 * 4</gadget>
<output>192</output>

<gadget id="calculator">135 + 192</gadget>
<output>327</output>

<result>327</result>