Okay, we are given 3066 and 6401. Let's add them up step by step.

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 6 & 0 in column 2 and get 6.

Step 3: We'll start by adding the digits 0 & 4 in column 3 and get 4.

Step 4: We'll start by adding the digits 3 & 6 in column 4 and get 9.

So, 3066 + 6401 = 9467.

