Xinhua Bookstore came in with a batch of storybooks, sold 400 copies in the morning and 440 copies in the afternoon, and there were still (2/5) of these storybooks left. How many books are left?
新华书店进来一批故事书，上午卖出400册，下午卖出440册，这时还剩这批故事书的(2/5)．还剩多少本？
<gadget id="calculator">400 + 440</gadget>
<output>840</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">840 / (3/5)</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 * (2/5)</gadget>
<output>560</output>

<result>560</result>