A batch of vegetables was shipped from New Century Supermarket, sold at the beginning (3/7), and there are 440 kilograms left. How many kilograms are there in this batch of vegetables?
新世纪超市运来一批蔬菜，卖初(3/7)，还剩440千克，这批蔬菜共有多少千克？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">440 / (4/7)</gadget>
<output>770</output>

<result>770</result>