Not to worry, we've got 6566 and 427. Let's get to adding them!

Step 1: We'll start by adding the digits 6 & 7 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 6 & 2 in column 2 and get 9.

Step 3: We'll start by adding the digits 5 & 4 in column 3 and get 9.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6566 + 427 = 6993.

