How many (2/21) are there in (6/7)．
(6/7)里面有多少个(2/21)．
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">2 / 21</gadget>
<output>2/21 = around 0.095238</output>

<gadget id="calculator">(6/7) / (2/21)</gadget>
<output>9</output>

<result>9</result>