stationery store can sell 157 homework books every day, after 24 days of selling, there are still 45 books left. How many homework books did the store originally have?
某文具店每天能卖出157本作业本，卖了24天，还剩下45本．这个商店原来有多少本作业本？
<gadget id="calculator">157 * 24</gadget>
<output>3_768</output>

<gadget id="calculator">3_768 + 45</gadget>
<output>3_813</output>

<result>3_813</result>