We are presented with 2002 and 6040. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 0 in column 1 and get 2.

Step 2: We'll start by adding the digits 0 & 4 in column 2 and get 4.

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

Step 4: We'll start by adding the digits 2 & 6 in column 4 and get 8.

So, 2002 + 6040 = 8042.

