Not to worry, we've got 375 and 312. Let's get to adding them!

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

Step 2: We'll start by adding the digits 7 & 1 in column 2 and get 8.

Step 3: We'll start by adding the digits 3 & 3 in column 3 and get 6.

So, 375 + 312 = 687.

