(3/4) of a number is 210, what is 30% of this number?
一个数的(3/4)是210，这个数的30%是多少．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">210 / (3/4)</gadget>
<output>280</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">280 * (3/10)</gadget>
<output>84</output>

<result>84</result>