Okay, we are tasked with adding 1970 and 8009. Let's begin!

Step 1: We'll start by adding the digits 0 & 9 in column 1 and get 9.

Step 2: We'll start by adding the digits 7 & 0 in column 2 and get 7.

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

Step 4: We'll start by adding the digits 1 & 8 in column 4 and get 9.

So, 1970 + 8009 = 9979.

