We divide 731760 by 21
The aim is to understand the frequency of 21 in 731760.

Advancing to step 1:
When dividing 7 by 21, we get 0 with a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Grab the next digit (3) from the dividend, add it to 7, then carry on: 73 / 21

Going ahead to step 2:
21 can be fit into 73 3 times, resulting in a remainder of 10.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 10 after subtracting 63 from 73.
Grab the next digit (1) from the dividend, add it to 10, then carry on: 101 / 21

Let's proceed to step 3:
21 goes into 101 4 times with a remainder of 17.
Use 4 as the next digit of our solution. 
Result so far: 34.0
The remainder is 17 after subtracting 84 from 101.
Append the next digit (7) from the dividend to 17 and continue with: 177 / 21

Step 4:
When dividing 177 by 21, we get 8 with a remainder of 9.
Write down 8 as next digit of the result. 
Result so far: 348.0
If we take 168 away from 177, we end up with 9.
Fetch the next digit (6) from the dividend, attach it to 9 and continue: 96 / 21

On to step 5:
If we divide 96 by 21, we get 4 and a remainder of 12.
The next digit of our result is 4. 
Result so far: 3484.0
Subtract 84 from 96 to get 12.
Take the next digit (0) from the dividend and append it to 12, then repeat: 120 / 21

Let's proceed to step 6:
21 can be fit into 120 5 times, resulting in a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 34845.0
Subtracting 105 from 120 leaves us 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.

Let's proceed to step 7:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 34845.7
If we subtract 147 from 150, we 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.

On to step 8:
21 goes into 30 1 times with a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 34845.71
Subtracting 21 from 30 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 9:
When dividing 90 by 21, we get 4 with a remainder of 6.
The next digit of our result is 4. 
Result so far: 34845.714
Deduct 84 from 90 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.

On to step 10:
If we divide 60 by 21, we get 2 and a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 34845.7142
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 11:
180 divided by 21 is 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 34845.71428
Subtract 168 from 180 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 12:
The number 21 fits into 120 5 times, leaving a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 34845.714285
The remainder is 15 after subtracting 105 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Step 13:
21 goes into 150 7 times with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 34845.7142857
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.

Step 14:
If we divide 30 by 21, we get 1 and a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 34845.71428571
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

After the division, we end up with 34845.71428571 and a remainder of 9e-09.