We've got two numbers: 3663 and 4031. Let's find their sum.

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 6 & 3 in column 2 and get 9.

Step 3: We'll start by adding the digits 6 & 0 in column 3 and get 6.

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

So, 3663 + 4031 = 7694.

