Okay, we are tasked with adding 7421 and 7962. Let's begin!

Step 1: We'll start by adding the digits 1 & 2 in column 1 and get 3.

Step 2: We'll start by adding the digits 2 & 6 in column 2 and get 8.

Step 3: We'll start by adding the digits 4 & 9 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 7 & 7 in column 4 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

So, 7421 + 7962 = 15383.

