Let's dive into this subtraction. We'll start with 386838 and subtract 42094 from it.

Step 1: We'll start by subtracting the digit 4 and the borrow 0 from 8 in column 1 and get 4.
4 is the first digit of our result.

Step 2: We'll start by subtracting the digit 9 and the borrow 0 from 3 in column 2 and get -6.
We add -6 to 10 and get 4 as the next digit of the result.

Step 3: We'll start by subtracting the digit 0 and the borrow 1 from 8 in column 3 and get 7.
7 is the next digit of our result.

Step 4: We'll start by subtracting the digit 2 and the borrow 0 from 6 in column 4 and get 4.
4 is the next digit of our result.

Step 5: We'll start by subtracting the digit 4 and the borrow 0 from 8 in column 5 and get 4.
4 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, 386838 - 42094 = 344744.