Ready to do some math? We're starting with 8099 and 6640 and adding them up.

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

Step 2: We'll start by adding the digits 9 & 4 in column 2 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 0 & 6 in column 3 and get 7.

Step 4: We'll start by adding the digits 8 & 6 in column 4 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

So, 8099 + 6640 = 14739.

