Primary school work and rest time: 7:50--10:50 in the morning; 2:30--5:30 in the afternoon. How many hours are you in school in a day?
小学作息时间上午7：50--10：50；下午2：30--5：30一天的在校时间是多少小时．
<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<result>6</result>