No problem, let's work through this together. We're starting with 516 and 456 and adding them all up.

Step 1: We'll start by adding the digits 6 & 6 in column 1 and get 12.
We'll write down the last digit 2 and carry the 1 to the next column.

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

Step 3: We'll start by adding the digits 5 & 4 in column 3 and get 9.

So, 516 + 456 = 972.

