Okay, we are given 2105 and 6791. Let's add them up step by step.

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 0 & 9 in column 2 and get 9.

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

Step 4: We'll start by adding the digits 2 & 6 in column 4 and get 8.

So, 2105 + 6791 = 8896.

