70% of a number is (2/3) of 210, find this number.
一个数的70%是210的(2/3)，求这个数．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(2/3) / (7/10)</gadget>
<output>20/21 = around 0.952381</output>

<gadget id="calculator">210 * (20/21)</gadget>
<output>200</output>

<result>200</result>