On a certain day in Jiangcheng, the highest temperature is 9°C, and the lowest temperature is -3°C. What is the difference between the highest temperature and the lowest temperature in degrees Celsius on this day?
江城某日的最高气温是9℃，最低气温是-3℃．这一天最高气温与最低气温相差多少摄氏度．
<gadget id="calculator">9 - (-3)</gadget>
<output>12</output>

<result>12</result>