On December 28, 2006, the highest temperature in Nanjing was 6 degrees Celsius, and the lowest temperature was -3 degrees Celsius, so what is the temperature difference on this day in degrees Celsius?
2006年12月28日，南京的最高气温是6摄氏度，最低气温是-3摄氏度，那么这天的温差是多少摄氏度．
<gadget id="calculator">6 - (-3)</gadget>
<output>9</output>

<result>9</result>