We are presented with 5015 and 1251. Let's work out the sum.

Step 1: We'll start by adding the digits 5 & 1 in column 1 and get 6.

Step 2: We'll start by adding the digits 1 & 5 in column 2 and get 6.

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 5 & 1 in column 4 and get 6.

So, 5015 + 1251 = 6266.

