We have numbers 8890 and 1531. Let's start adding them together.

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

Step 2: We'll start by adding the digits 9 & 3 in column 2 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 8 & 5 in column 3 and get 14.
We'll write down the last digit 4 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 1 in column 4 and get 10.
We'll write down the last digit 0 and carry the 1 to the next column.

So, 8890 + 1531 = 10421.

