The weather forecast in Tianjin on January 1, 2009 is -3 to 4 degrees Celsius. What is the temperature difference in Tianjin on this day in degrees Celsius?
2009年1月1日天津的天气预报是-3～4摄氏度，这天天津的温差是多少摄氏度．
<gadget id="calculator">4 - (-3)</gadget>
<output>7</output>

<result>7</result>