In the morning, the room temperature of Ethan\textquotesingle s house is $-5{}^{}\circ \text{C}$. At night, the room temperature of Ethan\textquotesingle s house becomes $10{}^{}\circ \text{C}$. What is the difference between temperature in the morning and temperature at night? 
Overseas Competition->Knowledge Point->Calculation Modules->Negative Numbers->Operations on Negative numbers