binding team binds an average of 285 books per day, 1425 books have been bound, and the rest will take 7 days to complete. How many books are there in this batch?
一个装订小组平均每天装订285本书，已经装订了1425本，余下的要7天完成，这批书一共有多少本？
<gadget id="calculator">285 * 7</gadget>
<output>1_995</output>

<gadget id="calculator">1_425 + 1_995</gadget>
<output>3_420</output>

<result>3_420</result>