No problem, let's work through this together. We're starting with 4017 and 2135 and adding them all up.

Step 1: We'll start by adding the digits 7 & 5 in column 1 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 1 & 3 in column 2 and get 5.

Step 3: We'll start by adding the digits 0 & 1 in column 3 and get 1.

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

So, 4017 + 2135 = 6152.

