Let's get this math done. We have 1601 and 4003 and we're going to add them all together.

Step 1: We'll start by adding the digits 1 & 3 in column 1 and get 4.

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

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 6.

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

So, 1601 + 4003 = 5604.

