Okay, we are given 4230 and 5648. Let's add them up step by step.

Step 1: We'll start by adding the digits 0 & 8 in column 1 and get 8.

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

Step 3: We'll start by adding the digits 2 & 6 in column 3 and get 8.

Step 4: We'll start by adding the digits 4 & 5 in column 4 and get 9.

So, 4230 + 5648 = 9878.

