There are 90 poplars in the campus, the willows are poplars (9/10), the willows are cypresses (7/9), how many cypresses are there in the school?
校园里有90棵杨树，柳树是杨树的(9/10)，柳树又是栢树的(7/9)，学校里的柏有多少棵？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">9 / 7</gadget>
<output>9/7 = around 1.285714</output>

<gadget id="calculator">(9/10) / (9/7)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">90 * (7/10)</gadget>
<output>63</output>

<result>63</result>