I went to bed at 9:00 in the evening and started to rest, and woke up at 7:00 the next morning. How many hours did I rest in total?
我从晚上9：00睡觉开始休息，到第二天早上7：00起床，一共休息了多少小时．
<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<result>10</result>