1. **State the problem:** The temperature in a freezer increased from $-23$ degrees Celsius to $3$ degrees Celsius over $2$ hours. We need to find the average change in temperature per hour. 2. **Identify the initial and final temperatures:** - Initial temperature, $T_i = -23$ degrees Celsius - Final temperature, $T_f = 3$ degrees Celsius 3. **Calculate the total change in temperature:** $$\Delta T = T_f - T_i = 3 - (-23) = 3 + 23 = 26$$ degrees Celsius 4. **Calculate the average change per hour:** The time interval is $2$ hours, so the average change per hour is $$\text{Average change} = \frac{\Delta T}{\text{time}} = \frac{26}{2} = 13$$ degrees Celsius per hour 5. **Final answer:** The average temperature increased by $13$ degrees Celsius each hour.