If the temperature is $−3^{\circ}C$ and it increased by $17^{\circ}C$ . What is the new temperature?
The starting point is $-3^{\circ}C$ and we move $17$ steps to right, where do we end up?
We move $3$ steps to get to $0$ meaning we are left with $14$ steps to the right of $0$, so we will stop at $14$.
Therefore our new temperature is $14^{\circ}C$