Let's break this down. We're going to add 316 and 641 together.

Step 1: We'll start by adding the digits 6 & 1 in column 1 and get 7.

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

Step 3: We'll start by adding the digits 3 & 6 in column 3 and get 9.

So, 316 + 641 = 957.

