Let's break this down. We're going to add 2387 and 3790 together.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

Step 2: We'll start by adding the digits 8 & 9 in column 2 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 3 & 7 in column 3 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 2 & 3 in column 4 and get 6.

So, 2387 + 3790 = 6177.

