OK, let's do this. We've got 2199 and 7087 and we're adding them all together.

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

Step 2: We'll start by adding the digits 9 & 8 in column 2 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 1 & 0 in column 3 and get 2.

Step 4: We'll start by adding the digits 2 & 7 in column 4 and get 9.

So, 2199 + 7087 = 9286.

