We've got two numbers: 8040 and 1423. Let's find their sum.

Step 1: We'll start by adding the digits 0 & 3 in column 1 and get 3.

Step 2: We'll start by adding the digits 4 & 2 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 8 & 1 in column 4 and get 9.

So, 8040 + 1423 = 9463.

