Here we go! We're going to add 9815 and 2031 together.

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 1 & 3 in column 2 and get 4.

Step 3: We'll start by adding the digits 8 & 0 in column 3 and get 8.

Step 4: We'll start by adding the digits 9 & 2 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 9815 + 2031 = 11846.

