We've got two numbers: 8220 and 8320. Let's find their sum.

Step 1: We'll start by adding the digits 0 & 0 in column 1 and get 0.

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

Step 3: We'll start by adding the digits 2 & 3 in column 3 and get 5.

Step 4: We'll start by adding the digits 8 & 8 in column 4 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

So, 8220 + 8320 = 16540.

