Fang Fang goes to bed at 8:00 every night and wakes up at 6:00 in the morning. How many hours does he sleep?
方方每天晚上8：00睡觉，早晨6：00起床，他的睡眠时间是几小时？
<gadget id="calculator">24 - 20</gadget>
<output>4</output>

<gadget id="calculator">6 - 0</gadget>
<output>6</output>

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

<result>10</result>