Okay, we are given 4228 and 4087. Let's add them up step by step.

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 2 & 8 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 2 & 0 in column 3 and get 3.

Step 4: We'll start by adding the digits 4 & 4 in column 4 and get 8.

So, 4228 + 4087 = 8315.

