Here we go! We're going to add 2409 and 140 together.

Step 1: We'll start by adding the digits 9 & 0 in column 1 and get 9.

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 4 & 1 in column 3 and get 5.

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

So, 2409 + 140 = 2549.

