We've got two numbers: 9531 and 5811. Let's find their sum.

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 3 & 1 in column 2 and get 4.

Step 3: We'll start by adding the digits 5 & 8 in column 3 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 9 & 5 in column 4 and get 15.
We'll write down the last digit 5 and carry the 1 to the next column.

So, 9531 + 5811 = 15342.

