No problem, let's work through this together. We're starting with 642538 and are subtracting 35820 from it.

Step 1: We'll start by subtracting the digit 0 and the borrow 0 from 8 in column 1 and get 8.
8 is the first digit of our result.

Step 2: We'll start by subtracting the digit 2 and the borrow 0 from 3 in column 2 and get 1.
1 is the next digit of our result.

Step 3: We'll start by subtracting the digit 8 and the borrow 0 from 5 in column 3 and get -3.
We add -3 to 10 and get 7 as the next digit of the result.

Step 4: We'll start by subtracting the digit 5 and the borrow 1 from 2 in column 4 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

Step 5: We'll start by subtracting the digit 3 and the borrow 1 from 4 in column 5 and get 0.
0 is the next digit of our result.

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

So, 642538 - 35820 = 606718.