At the spring sports meeting held by the school, Zhang Hong, Li Li and Sun Lan participated in the rope skipping competition. Zhang Hong jumped 216 times. Li Li jumped Zhang Hong's (7/8) and Sun Lan's (9/10) ). How many times did Sun Lan dance?
在学校举行的春季运动会上，张红、李丽、孙兰三人参加了跳绳比赛，张红跳了216个，李丽跳的是张红的(7/8)，是孙兰的(9/10)．孙兰跳了多少个？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(7/8) / (9/10)</gadget>
<output>35/36 = around 0.972222</output>

<gadget id="calculator">216 * (35/36)</gadget>
<output>210</output>

<result>210</result>