Let's get this math done. We have 2003 and 4912 and we're going to add them all together.

Step 1: We'll start by adding the digits 3 & 2 in column 1 and get 5.

Step 2: We'll start by adding the digits 0 & 1 in column 2 and get 1.

Step 3: We'll start by adding the digits 0 & 9 in column 3 and get 9.

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

So, 2003 + 4912 = 6915.

