If the temperature inside the classroom is +4°C and the temperature outside is -3°C, what is the difference between the temperature inside and outside the room in °C?
教室内温度为+4℃，室外温度为-3℃，那么室内外温度相差多少℃．
<gadget id="calculator">4 - (-3)</gadget>
<output>7</output>

<result>7</result>