We have numbers 8942 and 9986. Let's start adding them together.

Step 1: We'll start by adding the digits 2 & 6 in column 1 and get 8.

Step 2: We'll start by adding the digits 4 & 8 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 9 & 9 in column 3 and get 19.
We'll write down the last digit 9 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 8 & 9 in column 4 and get 18.
We'll write down the last digit 8 and carry the 1 to the next column.

So, 8942 + 9986 = 18928.

