OK, let's do this. We've got 3438 and 5173 and we're adding them all together.

Step 1: We'll start by adding the digits 8 & 3 in column 1 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 2: We'll start by adding the digits 3 & 7 in column 2 and get 11.
We'll write down the last digit 1 and carry the 1 to the next column.

Step 3: We'll start by adding the digits 4 & 1 in column 3 and get 6.

Step 4: We'll start by adding the digits 3 & 5 in column 4 and get 8.

So, 3438 + 5173 = 8611.

