We've got two numbers: 984 and 247. Let's find their sum.

Step 1: We'll start by adding the digits 4 & 7 in column 1 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 8 & 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 9 & 2 in column 3 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

So, 984 + 247 = 1231.

