We've got two numbers: 1554 and 1005. Let's find their sum.

Step 1: We'll start by adding the digits 4 & 5 in column 1 and get 9.

Step 2: We'll start by adding the digits 5 & 0 in column 2 and get 5.

Step 3: We'll start by adding the digits 5 & 0 in column 3 and get 5.

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

So, 1554 + 1005 = 2559.

