Okay, we are tasked with adding 5541 and 658. Let's begin!

Step 1: We'll start by adding the digits 1 & 8 in column 1 and get 9.

Step 2: We'll start by adding the digits 4 & 5 in column 2 and get 9.

Step 3: We'll start by adding the digits 5 & 6 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 5 & 0 in column 4 and get 6.

So, 5541 + 658 = 6199.

