Okay, we are tasked with adding 4503 and 5456. Let's begin!

Step 1: We'll start by adding the digits 3 & 6 in column 1 and get 9.

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 5 & 4 in column 3 and get 9.

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

So, 4503 + 5456 = 9959.

