The school bought 5 packs of extracurricular books, each pack has 4 bundles, and each bundle has 120 books. How many extracurricular books did the school buy?
学校买来5包课外书，每包有4捆，每捆有120本，学校买来了多少本课外书？
<gadget id="calculator">120 * 4 * 5</gadget>
<output>2_400</output>

<result>2_400</result>