The school library originally had 4,200 books, and the number of books has increased this year (3/20). How many books are there this year?
学校图书室原有图书4200册，今年图书册数增加了(3/20)．今年有图书多少册？
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 + (3/20)</gadget>
<output>23/20 = around 1.15</output>

<gadget id="calculator">4_200 * (23/20)</gadget>
<output>4_830</output>

<result>4_830</result>