Alright, let's solve this problem step by step. We have 210 and 625 and we're adding them together.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

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

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

So, 210 + 625 = 835.

