On a certain day, the highest temperature in Shanghai is 6°C, and the lowest temperature is -3°C. What is the temperature difference in Shanghai on this day?
某日上海市的最高气温是6℃，最低气温是-3℃，上海这天的温差是多少．
<gadget id="calculator">6 - (-3)</gadget>
<output>9</output>

<result>9</result>