We have numbers 637 and 1. Let's start adding them together.

Step 1: We'll start by adding the digits 7 & 1 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 0 in column 2 and get 3.

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

So, 637 + 1 = 638.

