Okay, we are given 4643 and 4276. Let's add them up step by step.

Step 1: We'll start by adding the digits 3 & 6 in column 1 and get 9.

Step 2: We'll start by adding the digits 4 & 7 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 6 & 2 in column 3 and get 9.

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

So, 4643 + 4276 = 8919.

