Okay, we are given 6351 and 625. Let's add them up step by step.

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

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

Step 3: We'll start by adding the digits 3 & 6 in column 3 and get 9.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6351 + 625 = 6976.

