Let's get this math done. We have 21 and 9031 and we're going to add them all together.

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

Step 2: We'll start by adding the digits 2 & 3 in column 2 and get 5.

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

Step 4: We'll start by adding the digits 0 & 9 in column 4 and get 9.

So, 21 + 9031 = 9052.

