Okay, we are tasked with adding 2135 and 4603. Let's begin!

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 0 in column 2 and get 3.

Step 3: We'll start by adding the digits 1 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 2 & 4 in column 4 and get 6.

So, 2135 + 4603 = 6738.

