Xinhua Bookstore shipped a batch of science and technology books, sold 249 copies in the morning, and sold as many copies in the afternoon as in the morning, leaving 72 copies left. How many science and technology books did Xinhua Bookstore ship in total?
新华书店运来一批科技书，上午卖出249本，下午卖出的本数和上午卖出的同样多，还剩72本．新华书店一共运来多少本科技书？
<gadget id="calculator">249 * 2</gadget>
<output>498</output>

<gadget id="calculator">498 + 72</gadget>
<output>570</output>

<result>570</result>