We're dividing 382584 by 21 
The aim is to understand the frequency of 21 in 382584.

Let's proceed to step 1:
When dividing 3 by 21, we get 0 with a remainder of 3.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 3 and we're left with 3.
Fetch the next digit (8) from the dividend, attach it to 3 and continue: 38 / 21

Step 2:
If we divide 38 by 21, we get 1 and a remainder of 17.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtract 21 from 38 to get 17.
Grab the next digit (2) from the dividend, add it to 17, then carry on: 172 / 21

Step 3:
172 divided by 21 is 8 with a remainder of 4.
The number 8 becomes the next digit in our result. 
Result so far: 18.0
The remainder is 4 after subtracting 168 from 172.
Include the next digit (5) from the dividend after 4, then repeat: 45 / 21

Moving on to step 4:
45 divided by 21 is 2 with a remainder of 3.
Put 2 as the next digit of the answer. 
Result so far: 182.0
Subtracting 42 from 45 leaves us with 3.
Take the next digit (8) from the dividend and append it to 3, then repeat: 38 / 21

Step 5:
The number 21 fits into 38 1 times, leaving a remainder of 17.
The next digit of our result is 1. 
Result so far: 1821.0
Subtract 21 from 38 to get 17.
Take the next digit (4) from the dividend and append it to 17, then repeat: 174 / 21

On to step 6:
The number 21 fits into 174 8 times, leaving a remainder of 6.
Record the quotient 8 as the next digit in the result. 
Result so far: 18218.0
Subtract 168 from 174 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 7:
If we divide 60 by 21, we get 2 and a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 18218.2
Subtracting 42 from 60 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 8:
180 divided by 21 is 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 18218.28
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 9:
120 divided by 21 is 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 18218.285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 10:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 18218.2857
Subtracting 147 from 150 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 11:
21 goes into 30 1 times with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 18218.28571
Subtracting 21 from 30 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 12:
If we divide 90 by 21, we get 4 and a remainder of 6.
The next digit of our result is 4. 
Result so far: 18218.285714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 13:
60 divided by 21 is 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 18218.2857142
Subtracting 42 from 60 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 14:
When dividing 180 by 21, we get 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 18218.28571428
Deduct 168 from 180 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Our division results in 18218.28571428 with a remaining 1.2e-08.