Okay, we are tasked with adding 5105 and 451. Let's begin!

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 0 & 5 in column 2 and get 5.

Step 3: We'll start by adding the digits 1 & 4 in column 3 and get 5.

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

So, 5105 + 451 = 5556.

