Let's break this down. We're going to add 1131 and 187 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 & 8 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

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

Step 4: We'll start by adding the digits 1 & 0 in column 4 and get 1.

So, 1131 + 187 = 1318.

