The highest temperature in Beijing on a certain day is 6°C, and the lowest temperature is -3°C, what is the temperature difference in this day?
北京某一天的最高气温是6℃，最低气温是-3℃，这一天的温差是多少℃．
<gadget id="calculator">6 - (-3)</gadget>
<output>9</output>

<result>9</result>