Okay, we are tasked with adding 4285 and 3499. Let's begin!

Step 1: We'll start by adding the digits 5 & 9 in column 1 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 8 & 9 in column 2 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 2 & 4 in column 3 and get 7.

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

So, 4285 + 3499 = 7784.

