The weather forecast in a certain place on March 8 is that the maximum temperature is 9°C and the minimum temperature is minus 2°C. What is the temperature difference on this day?
某地3月8日的天气预报是最高气温是9℃，最低气温零下2℃，这天的温差为多少℃．
<gadget id="calculator">9 - (-2)</gadget>
<output>11</output>

<result>11</result>