OK, let's do this. We've got 2529 and 355 and we're adding them all together.

Step 1: We'll start by adding the digits 9 & 5 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 5 in column 2 and get 8.

Step 3: We'll start by adding the digits 5 & 3 in column 3 and get 8.

Step 4: We'll start by adding the digits 2 & 0 in column 4 and get 2.

So, 2529 + 355 = 2884.

