No problem, let's work through this together. We're starting with 5203 and 5221 and adding them all up.

Step 1: We'll start by adding the digits 3 & 1 in column 1 and get 4.

Step 2: We'll start by adding the digits 0 & 2 in column 2 and get 2.

Step 3: We'll start by adding the digits 2 & 2 in column 3 and get 4.

Step 4: We'll start by adding the digits 5 & 5 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 5203 + 5221 = 10424.

