Okay, we are tasked with adding 1401 and 3515. Let's begin!

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

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 1.

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

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

So, 1401 + 3515 = 4916.

