Let's break this down. We're going to add 3385 and 4010 together.

Step 1: We'll start by adding the digits 5 & 0 in column 1 and get 5.

Step 2: We'll start by adding the digits 8 & 1 in column 2 and get 9.

Step 3: We'll start by adding the digits 3 & 0 in column 3 and get 3.

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

So, 3385 + 4010 = 7395.

