Let's break this down. We're going to add 4375 and 1504 together.

Step 1: We'll start by adding the digits 5 & 4 in column 1 and get 9.

Step 2: We'll start by adding the digits 7 & 0 in column 2 and get 7.

Step 3: We'll start by adding the digits 3 & 5 in column 3 and get 8.

Step 4: We'll start by adding the digits 4 & 1 in column 4 and get 5.

So, 4375 + 1504 = 5879.

