Not to worry, we've got 9924 and 1004. Let's get to adding them!

Step 1: We'll start by adding the digits 4 & 4 in column 1 and get 8.

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

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

Step 4: We'll start by adding the digits 9 & 1 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 9924 + 1004 = 10928.

