On a certain day in Shandan, the highest temperature is 8°C, and the lowest temperature is -7°C. What is the temperature difference on this day?
山丹某天的最高温度是8℃，最低温度是-7℃，这天的温差是多少．
<gadget id="calculator">8 - (-7)</gadget>
<output>15</output>

<result>15</result>