Okay, we are tasked with adding 6456 and 4813. Let's begin!

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

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

Step 3: We'll start by adding the digits 4 & 8 in column 3 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 6 & 4 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 6456 + 4813 = 11269.

