Not to worry, we've got 4003 and 1261. Let's get to adding them!

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 & 6 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 2 in column 3 and get 2.

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

So, 4003 + 1261 = 5264.

