Let's solve this addition problem. We have 1680 and 7804, and we need to add them together.

Step 1: We'll start by adding the digits 0 & 4 in column 1 and get 4.

Step 2: We'll start by adding the digits 8 & 0 in column 2 and get 8.

Step 3: We'll start by adding the digits 6 & 8 in column 3 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 1 & 7 in column 4 and get 9.

So, 1680 + 7804 = 9484.

