Okay, we are tasked with adding 401 and 6488. Let's begin!

Step 1: We'll start by adding the digits 1 & 8 in column 1 and get 9.

Step 2: We'll start by adding the digits 0 & 8 in column 2 and get 8.

Step 3: We'll start by adding the digits 4 & 4 in column 3 and get 8.

Step 4: We'll start by adding the digits 0 & 6 in column 4 and get 6.

So, 401 + 6488 = 6889.

