We are presented with 3634 and 1213. Let's work out the sum.

Step 1: We'll start by adding the digits 4 & 3 in column 1 and get 7.

Step 2: We'll start by adding the digits 3 & 1 in column 2 and get 4.

Step 3: We'll start by adding the digits 6 & 2 in column 3 and get 8.

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

So, 3634 + 1213 = 4847.

