834651 divided by 21 
The aim is to understand the frequency of 21 in 834651.

Advancing to step 1:
When dividing 8 by 21, we get 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Take the next digit (3) from the dividend and append it to 8, then repeat: 83 / 21

Let's proceed to step 2:
If we divide 83 by 21, we get 3 and a remainder of 20.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 20 after subtracting 63 from 83.
Include the next digit (4) from the dividend after 20, then repeat: 204 / 21

Advancing to step 3:
204 divided by 21 is 9 with a remainder of 15.
The number 9 becomes the next digit in our result. 
Result so far: 39.0
Subtracting 189 from 204 leaves us with 15.
Fetch the next digit (6) from the dividend, attach it to 15 and continue: 156 / 21

Advancing to step 4:
If we divide 156 by 21, we get 7 and a remainder of 9.
The number 7 becomes the next digit in our result. 
Result so far: 397.0
If we take 147 away from 156, we end up with 9.
Include the next digit (5) from the dividend after 9, then repeat: 95 / 21

On to step 5:
If we divide 95 by 21, we get 4 and a remainder of 11.
The next digit of our result is 4. 
Result so far: 3974.0
Subtract 84 from 95 to get 11.
Grab the next digit (1) from the dividend, add it to 11, then carry on: 111 / 21

Advancing to step 6:
The number 21 fits into 111 5 times, leaving a remainder of 6.
Use 5 as the next digit of our solution. 
Result so far: 39745.0
Deduct 105 from 111 and we're left 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.

Going ahead to step 7:
60 divided by 21 is 2 with a remainder of 18.
The next digit of our result is 2. 
Result so far: 39745.2
Subtract 42 from 60 to get 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:
When dividing 180 by 21, we get 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 39745.28
If we take 168 away from 180, we end up 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:
21 goes into 120 5 times with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 39745.285
Deduct 105 from 120 and we're left 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.

On to step 10:
If we divide 150 by 21, we get 7 and a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 39745.2857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Moving on to step 11:
30 divided by 21 is 1 with a remainder of 9.
The next digit of our result is 1. 
Result so far: 39745.28571
The remainder is 9 after subtracting 21 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 12:
When dividing 90 by 21, we get 4 with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 39745.285714
Subtracting 84 from 90 leaves us 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.

On to step 13:
If we divide 60 by 21, we get 2 and a remainder of 18.
The next digit of our result is 2. 
Result so far: 39745.2857142
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.

Let's proceed to step 14:
180 divided by 21 is 8 with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 39745.28571428
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.

The quotient of the division is 39745.28571428, and the remainder is 1.2e-08.