OK, let's do this. We've got 2425 and 8274 and we're adding them all together.

Step 1: We'll start by adding the digits 5 & 4 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 7 in column 2 and get 9.

Step 3: We'll start by adding the digits 4 & 2 in column 3 and get 6.

Step 4: We'll start by adding the digits 2 & 8 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 2425 + 8274 = 10699.

