902668 ÷ 21 
The aim is to understand the frequency of 21 in 902668.

Going ahead to step 1:
21 goes into 9 0 times with a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 9 to get 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 21

Let's proceed to step 2:
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: 4.0
If we subtract 84 from 90, we get 6.
Grab the next digit (2) from the dividend, add it to 6, then carry on: 62 / 21

Step 3:
The number 21 fits into 62 2 times, leaving a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 42.0
Deduct 42 from 62 and we're left with 20.
Take the next digit (6) from the dividend and append it to 20, then repeat: 206 / 21

On to step 4:
21 goes into 206 9 times with a remainder of 17.
Use 9 as the next digit of our solution. 
Result so far: 429.0
If we subtract 189 from 206, we get 17.
Take the next digit (6) from the dividend and append it to 17, then repeat: 176 / 21

Step 5:
The number 21 fits into 176 8 times, leaving a remainder of 8.
Write down 8 as next digit of the result. 
Result so far: 4298.0
Subtract 168 from 176 to get 8.
Fetch the next digit (8) from the dividend, attach it to 8 and continue: 88 / 21

Step 6:
21 can be fit into 88 4 times, resulting in a remainder of 4.
Write down 4 as next digit of the result. 
Result so far: 42984.0
The remainder is 4 after subtracting 84 from 88.
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 7:
40 divided by 21 is 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 42984.1
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 8:
21 goes into 190 9 times with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 42984.19
Subtracting 189 from 190 leaves us 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.

Going ahead to step 9:
If we divide 10 by 21, we get 0 and a remainder of 10.
The next digit of our result is 0. 
Result so far: 42984.19
Subtract 0 from 10 to get 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 10:
21 goes into 100 4 times with a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 42984.1904
Deduct 84 from 100 and we're left 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.

Going ahead to step 11:
21 goes into 160 7 times with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 42984.19047
Subtracting 147 from 160 leaves us 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.

Going ahead to step 12:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 42984.190476
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

On to step 13:
21 goes into 40 1 times with a remainder of 19.
The next digit of our result is 1. 
Result so far: 42984.1904761
If we take 21 away from 40, we end up 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.

On to step 14:
When dividing 190 by 21, we get 9 with a remainder of 1.
Use 9 as the next digit of our solution. 
Result so far: 42984.19047619
If we subtract 189 from 190, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

In conclusion, the division gives 42984.19047619 with a balance of 1e-09.