OK, let's do this. We've got 5205 and 4416 and we're adding them all together.

Step 1: We'll start by adding the digits 5 & 6 in column 1 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 2.

Step 3: We'll start by adding the digits 2 & 4 in column 3 and get 6.

Step 4: We'll start by adding the digits 5 & 4 in column 4 and get 9.

So, 5205 + 4416 = 9621.

