winter. The indoor temperature of Wang Yong’s house is 15°C, and the outdoor temperature is -5°C. How much higher is the indoor temperature than the outdoor temperature?
冬天．王永家室内温度是15℃，室外的温度是-5℃，室内的温度比室外的温度高多少℃．
<gadget id="calculator">15 - (-5)</gadget>
<output>20</output>

<result>20</result>