No problem, let's work through this together. We're starting with 21742 and are subtracting 21384 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 2 in column 1 and get -2.
We add -2 to 10 and get 8 as the first digit of the result.

Step 2: We'll start by subtracting the digit 8 and the borrow 1 from 4 in column 2 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 3: We'll start by subtracting the digit 3 and the borrow 1 from 7 in column 3 and get 3.
3 is the next digit of our result.

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

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

So, 21742 - 21384 = 358.