The school bought back 520 comic books, with an average cost of 4 yuan each. How much was the total cost of buying these comic books?
学校买回520本连环画，平均每本要4元，买这些连环画一共用了多少元？
<gadget id="calculator">4 * 520</gadget>
<output>2_080</output>

<result>2_080</result>