The school is going to distribute extra-curricular books to 16 classes, each class has 140 books, and 50 more books are needed as donations to the disaster-stricken areas. How many extra-curricular books should the school buy?
学校准备发课外书，发给16个班，每班140本，还需要50本作为捐赠灾区的物品，学校应买多少本课外书？
<gadget id="calculator">16 * 140</gadget>
<output>2_240</output>

<gadget id="calculator">2_240 + 50</gadget>
<output>2_290</output>

<result>2_290</result>