Let's break this down. We're going to add 1121 and 4343 together.

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

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

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

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

So, 1121 + 4343 = 5464.

