The total time when we add $1$ hour and $35$ minutes to $25$ minutes is $2$ hours.

To clarify how we reached this conclusion, let’s break it down step by step. First, we need to sum the minutes. We have $35$ minutes and $25$ minutes. When we add these two amounts, we calculate:

Next, it’s important to note that $60$ minutes is equivalent to $1$ hour. Therefore, we can convert these $60$ minutes into $1$ hour. Now, we add this $1$ hour to the original $1$ hour we started with. Thus, we have:

In conclusion, the total time when adding $1$ hour and $35$ minutes to $25$ minutes is indeed $2$ hours. This step-by-step approach can be very helpful for solving similar time addition problems in the future.