447967 ÷ 21 
The aim is to understand the frequency of 21 in 447967.

Advancing to step 1:
The number 21 fits into 4 0 times, leaving a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 4 after subtracting 0 from 4.
Append the next digit (4) from the dividend to 4 and continue with: 44 / 21

Let's proceed to step 2:
The number 21 fits into 44 2 times, leaving a remainder of 2.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 42 away from 44, we end up with 2.
Take the next digit (7) from the dividend and append it to 2, then repeat: 27 / 21

Advancing to step 3:
If we divide 27 by 21, we get 1 and a remainder of 6.
The next digit of our result is 1. 
Result so far: 21.0
The remainder is 6 after subtracting 21 from 27.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 21

Advancing to step 4:
If we divide 69 by 21, we get 3 and a remainder of 6.
The number 3 becomes the next digit in our result. 
Result so far: 213.0
If we subtract 63 from 69, we get 6.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 21

Advancing to step 5:
If we divide 66 by 21, we get 3 and a remainder of 3.
Write down 3 as next digit of the result. 
Result so far: 2133.0
If we take 63 away from 66, we end up with 3.
Take the next digit (7) from the dividend and append it to 3, then repeat: 37 / 21

On to step 6:
When dividing 37 by 21, we get 1 with a remainder of 16.
Use 1 as the next digit of our solution. 
Result so far: 21331.0
Subtracting 21 from 37 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.

Going ahead to step 7:
If we divide 160 by 21, we get 7 and a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 21331.7
If we subtract 147 from 160, we 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.

Let's proceed to step 8:
21 can be fit into 130 6 times, resulting in a remainder of 4.
The next digit of our result is 6. 
Result so far: 21331.76
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.

Going ahead to step 9:
21 goes into 40 1 times with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 21331.761
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 10:
When dividing 190 by 21, we get 9 with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 21331.7619
Subtract 189 from 190 to 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.

Moving on to step 11:
The number 21 fits into 10 0 times, leaving a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 21331.7619
If we take 0 away from 10, we end up 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.

On to step 12:
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: 21331.761904
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.

Moving on to step 13:
When dividing 160 by 21, we get 7 with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 21331.7619047
If we subtract 147 from 160, we 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.

Let's proceed to step 14:
21 goes into 130 6 times with a remainder of 4.
The next digit of our result is 6. 
Result so far: 21331.76190476
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.

The final result is 21331.76190476 with a remainder of 4e-09.