Alright, let's solve this problem step by step. We have 2378 and 2307 and we're adding them together.

Step 1: We'll start by adding the digits 8 & 7 in column 1 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 7 & 0 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 & 2 in column 4 and get 4.

So, 2378 + 2307 = 4685.

