Pingping goes to bed at 8 o'clock every night and wakes up at 6 o'clock in the morning. How many hours does he sleep every day?
平平每晚8时睡觉，早上6时起床，他每天睡多少小时．
<gadget id="calculator">24 - 20</gadget>
<output>4</output>

<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<result>10</result>