Let's get this math done. We have 1003 and 3781 and we're going to add them all together.

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

Step 2: We'll start by adding the digits 0 & 8 in column 2 and get 8.

Step 3: We'll start by adding the digits 0 & 7 in column 3 and get 7.

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

So, 1003 + 3781 = 4784.

