Let's break this down. We're going to add 531 and 7100 together.

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

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 5 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 0 & 7 in column 4 and get 7.

So, 531 + 7100 = 7631.

