Okay, we are tasked with adding 1252 and 7191. Let's begin!

Step 1: We'll start by adding the digits 2 & 1 in column 1 and get 3.

Step 2: We'll start by adding the digits 5 & 9 in column 2 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 2 & 1 in column 3 and get 4.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 8.

So, 1252 + 7191 = 8443.

