We are presented with 4906 and 8891. Let's work out the sum.

Step 1: We'll start by adding the digits 6 & 1 in column 1 and get 7.

Step 2: We'll start by adding the digits 0 & 9 in column 2 and get 9.

Step 3: We'll start by adding the digits 9 & 8 in column 3 and get 17.
We'll write down the last digit 7 and carry the 1 to the next column.

Step 4: We'll start by adding the digits 4 & 8 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 4906 + 8891 = 13797.

