Ready to do some math? We're starting with 816 and 723 and adding them up.

Step 1: We'll start by adding the digits 6 & 3 in column 1 and get 9.

Step 2: We'll start by adding the digits 1 & 2 in column 2 and get 3.

Step 3: We'll start by adding the digits 8 & 7 in column 3 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

So, 816 + 723 = 1539.

