We've got two numbers: 6602 and 2042. Let's find their sum.

Step 1: We'll start by adding the digits 2 & 2 in column 1 and get 4.

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

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 6.

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

So, 6602 + 2042 = 8644.

