certain primary school lent newly purchased books to 26 classes, with an average of 40 books per class, and 830 books left. How many books did the school buy this time?
某小学把新买的图书借给26个班，平均每班借40本，还剩830本，这次学校新买了多少本图书？
<gadget id="calculator">40 * 26</gadget>
<output>1_040</output>

<gadget id="calculator">1_040 + 830</gadget>
<output>1_870</output>

<result>1_870</result>