Let's break this down. We're going to add 1181 and 3409 together.

Step 1: We'll start by adding the digits 1 & 9 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 8 & 0 in column 2 and get 9.

Step 3: We'll start by adding the digits 1 & 4 in column 3 and get 5.

Step 4: We'll start by adding the digits 1 & 3 in column 4 and get 4.

So, 1181 + 3409 = 4590.

