We are presented with 8358 and 3220. Let's work out the sum.

Step 1: We'll start by adding the digits 8 & 0 in column 1 and get 8.

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

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

Step 4: We'll start by adding the digits 8 & 3 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 8358 + 3220 = 11578.

