No problem, let's work through this together. We're starting with 2390 and 5105 and adding them all up.

Step 1: We'll start by adding the digits 0 & 5 in column 1 and get 5.

Step 2: We'll start by adding the digits 9 & 0 in column 2 and get 9.

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

Step 4: We'll start by adding the digits 2 & 5 in column 4 and get 7.

So, 2390 + 5105 = 7495.

