We are presented with 6842 and 6305. Let's work out the sum.

Step 1: We'll start by adding the digits 2 & 5 in column 1 and get 7.

Step 2: We'll start by adding the digits 4 & 0 in column 2 and get 4.

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

Step 4: We'll start by adding the digits 6 & 6 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 6842 + 6305 = 13147.

