Okay, we are tasked with adding 558 and 164. Let's begin!

Step 1: We'll start by adding the digits 8 & 4 in column 1 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 5 & 6 in column 2 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 5 & 1 in column 3 and get 7.

So, 558 + 164 = 722.

