We are presented with 8910 and 2986. Let's work out the sum.

Step 1: We'll start by adding the digits 0 & 6 in column 1 and get 6.

Step 2: We'll start by adding the digits 1 & 8 in column 2 and get 9.

Step 3: We'll start by adding the digits 9 & 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 8 & 2 in column 4 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

So, 8910 + 2986 = 11896.

