Let's solve this addition problem. We have 7321 and 9517, and we need to add them together.

Step 1: We'll start by adding the digits 1 & 7 in column 1 and get 8.

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

Step 3: We'll start by adding the digits 3 & 5 in column 3 and get 8.

Step 4: We'll start by adding the digits 7 & 9 in column 4 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

So, 7321 + 9517 = 16838.

