Okay, we are given 4198 and 7785. Let's add them up step by step.

Step 1: We'll start by adding the digits 8 & 5 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 9 & 8 in column 2 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 9.

Step 4: We'll start by adding the digits 4 & 7 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 4198 + 7785 = 11983.

