Let's break this down. We're going to add 4855 and 956 together.

Step 1: We'll start by adding the digits 5 & 6 in column 1 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 5 & 5 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 8 & 9 in column 3 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 4 & 0 in column 4 and get 5.

So, 4855 + 956 = 5811.

