We have numbers 1003 and 1344. Let's start adding them together.

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 4.

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

Step 4: We'll start by adding the digits 1 & 1 in column 4 and get 2.

So, 1003 + 1344 = 2347.

