Not to worry, we've got 3851 and 4142. Let's get to adding them!

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

Step 2: We'll start by adding the digits 5 & 4 in column 2 and get 9.

Step 3: We'll start by adding the digits 8 & 1 in column 3 and get 9.

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

So, 3851 + 4142 = 7993.

