We look at the division of 949087 by 21 
The aim is to understand the frequency of 21 in 949087.

On to step 1:
21 goes into 9 0 times with a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Fetch the next digit (4) from the dividend, attach it to 9 and continue: 94 / 21

Let's proceed to step 2:
When dividing 94 by 21, we get 4 with a remainder of 10.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we subtract 84 from 94, we get 10.
Take the next digit (9) from the dividend and append it to 10, then repeat: 109 / 21

On to step 3:
When dividing 109 by 21, we get 5 with a remainder of 4.
Record the quotient 5 as the next digit in the result. 
Result so far: 45.0
Deduct 105 from 109 and we're left with 4.
Bring next digit (0) of the dividend behind the 4 and repeat the process: 40 / 21

Going ahead to step 4:
The number 21 fits into 40 1 times, leaving a remainder of 19.
The next digit of our result is 1. 
Result so far: 451.0
The remainder is 19 after subtracting 21 from 40.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 21

On to step 5:
21 can be fit into 198 9 times, resulting in a remainder of 9.
The next digit of our result is 9. 
Result so far: 4519.0
Subtracting 189 from 198 leaves us with 9.
Take the next digit (7) from the dividend and append it to 9, then repeat: 97 / 21

Let's proceed to step 6:
The number 21 fits into 97 4 times, leaving a remainder of 13.
The next digit of our result is 4. 
Result so far: 45194.0
Deduct 84 from 97 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 7:
21 goes into 130 6 times with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 45194.6
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 8:
40 divided by 21 is 1 with a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 45194.61
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 9:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The next digit of our result is 9. 
Result so far: 45194.619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 10:
When dividing 10 by 21, we get 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 45194.619
Subtracting 0 from 10 leaves us 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 11:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 45194.61904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 12:
21 goes into 160 7 times with a remainder of 13.
The next digit of our result is 7. 
Result so far: 45194.619047
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 13:
21 goes into 130 6 times with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 45194.6190476
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 14:
40 divided by 21 is 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 45194.61904761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

The quotient of the division is 45194.61904761, and the remainder is 1.9e-08.