We are presented with 15 and 8242. Let's work out the sum.

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

Step 2: We'll start by adding the digits 1 & 4 in column 2 and get 5.

Step 3: We'll start by adding the digits 0 & 2 in column 3 and get 2.

Step 4: We'll start by adding the digits 0 & 8 in column 4 and get 8.

So, 15 + 8242 = 8257.

