Let's solve this addition problem. We have 5122 and 4115, and we need to add them together.

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

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

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

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

So, 5122 + 4115 = 9237.

