We can solve this together! We're beginning with 352935 and removing 21804 from it.

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

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

Step 3: We'll start by subtracting the digit 8 and the borrow 0 from 9 in column 3 and get 1.
1 is the next digit of our result.

Step 4: We'll start by subtracting the digit 1 and the borrow 0 from 2 in column 4 and get 1.
1 is the next digit of our result.

Step 5: We'll start by subtracting the digit 2 and the borrow 0 from 5 in column 5 and get 3.
3 is the next digit of our result.

Step 6: We'll start by subtracting the digit 0 and the borrow 0 from 3 in column 6 and get 3.
3 is the next digit of our result.

So, 352935 - 21804 = 331131.