Okay, we are given 6213 and 8612. Let's add them up step by step.

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

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

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

Step 4: We'll start by adding the digits 6 & 8 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 6213 + 8612 = 14825.

