Let's solve this addition problem. We have 7865 and 1013, and we need to add them together.

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

Step 2: We'll start by adding the digits 6 & 1 in column 2 and get 7.

Step 3: We'll start by adding the digits 8 & 0 in column 3 and get 8.

Step 4: We'll start by adding the digits 7 & 1 in column 4 and get 8.

So, 7865 + 1013 = 8878.

