No problem, let's work through this together. We're starting with 251 and 707 and adding them all up.

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

Step 2: We'll start by adding the digits 5 & 0 in column 2 and get 5.

Step 3: We'll start by adding the digits 2 & 7 in column 3 and get 9.

So, 251 + 707 = 958.

