On a certain day, the temperature in Beijing is -8°C, and the temperature in Hainan is 12°C. What is the temperature difference between Beijing and Hainan on this day?
某日北京的气温是-8℃，海南的气温是12℃，这天北京和海南的温差是多少
<gadget id="calculator">12 - (-8)</gadget>
<output>20</output>

<result>20</result>