No problem, let's work through this together. We're starting with 5366 and 9415 and adding them all up.

Step 1: We'll start by adding the digits 6 & 5 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 6 & 1 in column 2 and get 8.

Step 3: We'll start by adding the digits 3 & 4 in column 3 and get 7.

Step 4: We'll start by adding the digits 5 & 9 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 5366 + 9415 = 14781.

