OK, let's do this. We've got 772 and 94 and we're adding them all together.

Step 1: We'll start by adding the digits 2 & 4 in column 1 and get 6.

Step 2: We'll start by adding the digits 7 & 9 in column 2 and get 16.
We'll write down the last digit 6 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 7 & 0 in column 3 and get 8.

So, 772 + 94 = 866.

