The transport team wants to transport a batch of flour. The first time transports all (3/7), and the second time transports all (2/7). The two times transported a total of 450 tons. How many tons are there in this batch of flour?
运输队要运输一批面粉，第一次运走全部的(3/7)，第二次运走全部的(2/7)，两次共运走了450吨，这批面粉共有多少吨？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(3/7) + (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">450 / (5/7)</gadget>
<output>630</output>

<result>630</result>