Lingling went to bed at 9:00 last night and woke up at 6:00 this morning. How long did Lingling sleep in total?
玲玲昨天晚上9：00睡觉，今天早上6：00起床，玲玲一共睡了多长时间？
<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<result>9</result>