Okay, we are given 2377 and 1612. Let's add them up step by step.

Step 1: We'll start by adding the digits 7 & 2 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 & 6 in column 3 and get 9.

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

So, 2377 + 1612 = 3989.

