We have numbers 7887 and 5981. Let's start adding them together.

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

Step 2: We'll start by adding the digits 8 & 8 in column 2 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 8 & 9 in column 3 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 7 & 5 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 7887 + 5981 = 13868.

