We have numbers 5712 and 5621. Let's start adding them together.

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

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 7 & 6 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 5 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 5712 + 5621 = 11333.

