Let's solve this addition problem. We have 7125 and 6734, and we need to add them together.

Step 1: We'll start by adding the digits 5 & 4 in column 1 and get 9.

Step 2: We'll start by adding the digits 2 & 3 in column 2 and get 5.

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

Step 4: We'll start by adding the digits 7 & 6 in column 4 and get 13.
We'll write down the last digit 3 and carry the 1 to the next column.

So, 7125 + 6734 = 13859.

