OK, let's do this. We've got 8431 and 6530 and we're adding them all together.

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

Step 2: We'll start by adding the digits 3 & 3 in column 2 and get 6.

Step 3: We'll start by adding the digits 4 & 5 in column 3 and get 9.

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

So, 8431 + 6530 = 14961.

