We're dividing 390643 by 84 
Our goal is to divide 390643 by 84.

Moving on to step 1:
When dividing 3 by 84, we get 0 with a remainder of 3.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Take the next digit (9) from the dividend and append it to 3, then repeat: 39 / 84

Let's proceed to step 2:
39 divided by 84 is 0 with a remainder of 39.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 39 to get 39.
Fetch the next digit (0) from the dividend, attach it to 39 and continue: 390 / 84

Advancing to step 3:
If we divide 390 by 84, we get 4 and a remainder of 54.
Put 4 as the next digit of the answer. 
Result so far: 4.0
Subtracting 336 from 390 leaves us with 54.
Grab the next digit (6) from the dividend, add it to 54, then carry on: 546 / 84

On to step 4:
84 goes into 546 6 times with a remainder of 42.
Record the quotient 6 as the next digit in the result. 
Result so far: 46.0
Subtract 504 from 546 to get 42.
Fetch the next digit (4) from the dividend, attach it to 42 and continue: 424 / 84

Step 5:
The number 84 fits into 424 5 times, leaving a remainder of 4.
The number 5 becomes the next digit in our result. 
Result so far: 465.0
Subtracting 420 from 424 leaves us with 4.
Append the next digit (3) from the dividend to 4 and continue with: 43 / 84

Let's proceed to step 6:
43 divided by 84 is 0 with a remainder of 43.
Record the quotient 0 as the next digit in the result. 
Result so far: 4650.0
Deduct 0 from 43 and we're left with 43.
Since there are no more digits in the dividend, we add a zero to the remainder making it 430, and continue the process.

Moving on to step 7:
84 goes into 430 5 times with a remainder of 10.
Use 5 as the next digit of our solution. 
Result so far: 4650.5
Deduct 420 from 430 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 8:
If we divide 100 by 84, we get 1 and a remainder of 16.
The next digit of our result is 1. 
Result so far: 4650.51
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 9:
84 goes into 160 1 times with a remainder of 76.
The next digit of our result is 1. 
Result so far: 4650.511
Subtracting 84 from 160 leaves us with 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

After the division, we end up with 4650.511 and a remainder of 0.0076.