We have numbers 1667 and 6309. Let's start adding them together.

Step 1: We'll start by adding the digits 7 & 9 in column 1 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 6 & 0 in column 2 and get 7.

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

Step 4: We'll start by adding the digits 1 & 6 in column 4 and get 7.

So, 1667 + 6309 = 7976.

