OK, let's do this. We've got 166 and 707 and we're adding them all together.

Step 1: We'll start by adding the digits 6 & 7 in column 1 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 6 & 0 in column 2 and get 7.

Step 3: We'll start by adding the digits 1 & 7 in column 3 and get 8.

So, 166 + 707 = 873.

