We have numbers 3077 and 3070. Let's start adding them together.

Step 1: We'll start by adding the digits 7 & 0 in column 1 and get 7.

Step 2: We'll start by adding the digits 7 & 7 in column 2 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 0 in column 3 and get 1.

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

So, 3077 + 3070 = 6147.

