We divide 284707 by 21
The aim is to understand the frequency of 21 in 284707.

Step 1:
The number 21 fits into 2 0 times, leaving a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Grab the next digit (8) from the dividend, add it to 2, then carry on: 28 / 21

Step 2:
If we divide 28 by 21, we get 1 and a remainder of 7.
Write down 1 as next digit of the result. 
Result so far: 1.0
The remainder is 7 after subtracting 21 from 28.
Append the next digit (4) from the dividend to 7 and continue with: 74 / 21

Advancing to step 3:
74 divided by 21 is 3 with a remainder of 11.
Write down 3 as next digit of the result. 
Result so far: 13.0
If we subtract 63 from 74, we get 11.
Include the next digit (7) from the dividend after 11, then repeat: 117 / 21

Going ahead to step 4:
21 can be fit into 117 5 times, resulting in a remainder of 12.
Write down 5 as next digit of the result. 
Result so far: 135.0
If we subtract 105 from 117, we get 12.
Append the next digit (0) from the dividend to 12 and continue with: 120 / 21

Advancing to step 5:
21 goes into 120 5 times with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 1355.0
If we subtract 105 from 120, we get 15.
Append the next digit (7) from the dividend to 15 and continue with: 157 / 21

Advancing to step 6:
The number 21 fits into 157 7 times, leaving a remainder of 10.
Record the quotient 7 as the next digit in the result. 
Result so far: 13557.0
The remainder is 10 after subtracting 147 from 157.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 7:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 13557.4
Subtract 84 from 100 to get 16.
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 8:
If we divide 160 by 21, we get 7 and a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 13557.47
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 9:
21 goes into 130 6 times with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 13557.476
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.

Going ahead to step 10:
21 can be fit into 40 1 times, resulting in a remainder of 19.
The next digit of our result is 1. 
Result so far: 13557.4761
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.

Going ahead to step 11:
When dividing 190 by 21, we get 9 with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 13557.47619
Deduct 189 from 190 and we're left 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 12:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 13557.47619
Deduct 0 from 10 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 13:
The number 21 fits into 100 4 times, leaving a remainder of 16.
The next digit of our result is 4. 
Result so far: 13557.4761904
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.

On to step 14:
160 divided by 21 is 7 with a remainder of 13.
The next digit of our result is 7. 
Result so far: 13557.47619047
Subtract 147 from 160 to get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final result is 13557.47619047 with a remainder of 1.3e-08.