Here we go! We're going to add 5591 and 8771 together.

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

Step 2: We'll start by adding the digits 9 & 7 in column 2 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 5 & 7 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 8 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 5591 + 8771 = 14362.

