Let's break this down. We're going to add 2373 and 1316 together.

Step 1: We'll start by adding the digits 3 & 6 in column 1 and get 9.

Step 2: We'll start by adding the digits 7 & 1 in column 2 and get 8.

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

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

So, 2373 + 1316 = 3689.

