We are presented with 455 and 331. Let's work out the sum.

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 5 & 3 in column 2 and get 8.

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

So, 455 + 331 = 786.

