Let's solve this addition problem. We have 6216 and 2551, and we need to add them together.

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

Step 2: We'll start by adding the digits 1 & 5 in column 2 and get 6.

Step 3: We'll start by adding the digits 2 & 5 in column 3 and get 7.

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

So, 6216 + 2551 = 8767.

