According to the statistics of the campus library, the third grade borrows an average of 63 books per class, and the fourth grade borrows an average of 77 books per class. There are 5 classes in each of the two grades. How many books are borrowed in total for the third and fourth grades?
学校园书馆统考计，三年级平均每班借书63本，四年级平均每班借书77本，两个年级各有5个班，三、四年级一共借阅图书多少本？
<gadget id="calculator">63 * 5</gadget>
<output>315</output>

<gadget id="calculator">77 * 5</gadget>
<output>385</output>

<gadget id="calculator">315 + 385</gadget>
<output>700</output>

<result>700</result>