Okay, we are given 8972 and 2928. Let's add them up step by step.

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

Step 2: We'll start by adding the digits 7 & 2 in column 2 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 9 & 9 in column 3 and get 19.
We'll write down the last digit 9 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 2 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 8972 + 2928 = 11900.

