In a certain place, the lowest temperature in one day is -6°C and the highest temperature is 12°C. What is the difference between the highest temperature and the lowest temperature in this day?
某地有一天的最低气温是-6℃，最高气温是12℃，这一天的最高气温与最低气温相差多少度．
<gadget id="calculator">12 - (-6)</gadget>
<output>18</output>

<result>18</result>