Here we go! We're going to add 6443 and 2133 together.

Step 1: We'll start by adding the digits 3 & 3 in column 1 and get 6.

Step 2: We'll start by adding the digits 4 & 3 in column 2 and get 7.

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

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

So, 6443 + 2133 = 8576.

