We are presented with 621 and 132. Let's work out the sum.

Step 1: We'll start by adding the digits 1 & 2 in column 1 and get 3.

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

Step 3: We'll start by adding the digits 6 & 1 in column 3 and get 7.

So, 621 + 132 = 753.

