Alright, let's solve this problem step by step. We have 607109650 and 589021850, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 0 and the borrow 0 from 0 in column 1 and get 0.
0 is the first digit of our result.

Step 2: We'll start by subtracting the digit 5 and the borrow 0 from 5 in column 2 and get 0.
0 is the next digit of our result.

Step 3: We'll start by subtracting the digit 8 and the borrow 0 from 6 in column 3 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 4: We'll start by subtracting the digit 1 and the borrow 1 from 9 in column 4 and get 7.
7 is the next digit of our result.

Step 5: We'll start by subtracting the digit 2 and the borrow 0 from 0 in column 5 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 6: We'll start by subtracting the digit 0 and the borrow 1 from 1 in column 6 and get 0.
0 is the next digit of our result.

Step 7: We'll start by subtracting the digit 9 and the borrow 0 from 7 in column 7 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 8: We'll start by subtracting the digit 8 and the borrow 1 from 0 in column 8 and get -9.
We add -9 to 10 and get 1 as the next digit of the result.

Step 9: We'll start by subtracting the digit 5 and the borrow 1 from 6 in column 9 and get 0.
0 is the next digit of our result.

So, 607109650 - 589021850 = 18087800.