Let's solve this addition problem. We have 602 and 2173, and we need to add them together.

Step 1: We'll start by adding the digits 2 & 3 in column 1 and get 5.

Step 2: We'll start by adding the digits 0 & 7 in column 2 and get 7.

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 7.

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

So, 602 + 2173 = 2775.

