Okay, we are tasked with adding 2021 and 5449. Let's begin!

Step 1: We'll start by adding the digits 1 & 9 in column 1 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 2 & 4 in column 2 and get 7.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 2 & 5 in column 4 and get 7.

So, 2021 + 5449 = 7470.

