Alright, let's solve this problem step by step. We have 7121 and 371 and we're adding them together.

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

Step 2: We'll start by adding the digits 2 & 7 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 7 & 0 in column 4 and get 7.

So, 7121 + 371 = 7492.

