Here we go! We're going to add 6515 and 153 together.

Step 1: We'll start by adding the digits 5 & 3 in column 1 and get 8.

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 5 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 6 & 0 in column 4 and get 6.

So, 6515 + 153 = 6668.

