The fruit store came in with 490 kilograms of apples, packed in a box of 7 kilograms, and sold 40 boxes. How many boxes of apples are there in the fruit store?
水果店进来490千克苹果，每7千克装一箱，已经卖出了40箱，水果店里还有多少箱苹果？
<gadget id="calculator">490 / 7</gadget>
<output>70</output>

<gadget id="calculator">70 - 40</gadget>
<output>30</output>

<result>30</result>