OK, let's do this. We've got 7043 and 9924 and we're adding them all together.

Step 1: We'll start by adding the digits 3 & 4 in column 1 and get 7.

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

Step 3: We'll start by adding the digits 0 & 9 in column 3 and get 9.

Step 4: We'll start by adding the digits 7 & 9 in column 4 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

So, 7043 + 9924 = 16967.

