Let's solve this addition problem. We have 861 and 5002, and we need to add them together.

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 6 & 0 in column 2 and get 6.

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 0 & 5 in column 4 and get 5.

So, 861 + 5002 = 5863.

