The factory supports the disaster area to make tents. (2/3) of this batch of tents has been produced. If 210 more tents have been produced, (3/4) of this batch of tents has been produced. How many tents are there in total?
工厂支援灾区做帐篷，已生产这批帐篷的(2/3)，如果再生产210个，已生产的正好是这批帐篷的(3/4)，这批帐篷一共有多少个．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(3/4) - (2/3)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">210 / (1/12)</gadget>
<output>2_520</output>

<result>2_520</result>