There are 50 sets of story books in the library, each set has 2 books, and each story book is 45 yuan. Please help Uncle Li in the library calculate how much these books are worth in total?
图书馆里有50套故事书，每套2本，每本故事书45元，请你帮图书馆的李叔叔算一算这些图书一共多少元？
<gadget id="calculator">50 * 2 * 45</gadget>
<output>4_500</output>

<result>4_500</result>