Alright, let's solve this problem step by step. We have 5680 and 4199 and we're adding them together.

Step 1: We'll start by adding the digits 0 & 9 in column 1 and get 9.

Step 2: We'll start by adding the digits 8 & 9 in column 2 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 8.

Step 4: We'll start by adding the digits 5 & 4 in column 4 and get 9.

So, 5680 + 4199 = 9879.

