Not to worry, we've got 448 and 8311. Let's get to adding them!

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

Step 2: We'll start by adding the digits 4 & 1 in column 2 and get 5.

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

Step 4: We'll start by adding the digits 0 & 8 in column 4 and get 8.

So, 448 + 8311 = 8759.

