Let's break this down. We're going to add 3131 and 497 together.

Step 1: We'll start by adding the digits 1 & 7 in column 1 and get 8.

Step 2: We'll start by adding the digits 3 & 9 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 1 & 4 in column 3 and get 6.

Step 4: We'll start by adding the digits 3 & 0 in column 4 and get 3.

So, 3131 + 497 = 3628.

