Let's break this down. We're going to add 1640 and 9710 together.

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

Step 2: We'll start by adding the digits 4 & 1 in column 2 and get 5.

Step 3: We'll start by adding the digits 6 & 7 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 1 & 9 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 1640 + 9710 = 11350.

