Okay, we are tasked with adding 1871 and 3004. Let's begin!

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

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 8 & 0 in column 3 and get 8.

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

So, 1871 + 3004 = 4875.

