We are presented with 3 and 966. Let's work out the sum.

Step 1: We'll start by adding the digits 3 & 6 in column 1 and get 9.

Step 2: We'll start by adding the digits 0 & 6 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 9 in column 3 and get 9.

So, 3 + 966 = 969.

