No problem, let's work through this together. We're starting with 1269 and 7519 and adding them all up.

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

Step 2: We'll start by adding the digits 6 & 1 in column 2 and get 8.

Step 3: We'll start by adding the digits 2 & 5 in column 3 and get 7.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1269 + 7519 = 8788.

