We divide 741939 by 21
The aim is to understand the frequency of 21 in 741939.

On to step 1:
The number 21 fits into 7 0 times, leaving a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Append the next digit (4) from the dividend to 7 and continue with: 74 / 21

Moving on to step 2:
21 goes into 74 3 times with a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 63 from 74 and we're left with 11.
Append the next digit (1) from the dividend to 11 and continue with: 111 / 21

Moving on to step 3:
21 goes into 111 5 times with a remainder of 6.
The next digit of our result is 5. 
Result so far: 35.0
Deduct 105 from 111 and we're left with 6.
Append the next digit (9) from the dividend to 6 and continue with: 69 / 21

Going ahead to step 4:
The number 21 fits into 69 3 times, leaving a remainder of 6.
Record the quotient 3 as the next digit in the result. 
Result so far: 353.0
Subtract 63 from 69 to get 6.
Bring next digit (3) of the dividend behind the 6 and repeat the process: 63 / 21

Let's proceed to step 5:
21 goes into 63 3 times with a remainder of 0.
Record the quotient 3 as the next digit in the result. 
Result so far: 3533.0
If we take 63 away from 63, we end up with 0.
Fetch the next digit (9) from the dividend, attach it to 0 and continue: 9 / 21

Moving on to step 6:
21 goes into 9 0 times with a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 35330.0
Deduct 0 from 9 and we're left 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.

Moving on to step 7:
If we divide 90 by 21, we get 4 and a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 35330.4
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 8:
60 divided by 21 is 2 with a remainder of 18.
The next digit of our result is 2. 
Result so far: 35330.42
If we take 42 away from 60, we end up 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.

Advancing to step 9:
21 goes into 180 8 times with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 35330.428
If we subtract 168 from 180, we 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 10:
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: 35330.4285
If we subtract 105 from 120, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 11:
21 goes into 150 7 times with a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 35330.42857
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.

Let's proceed to step 12:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 35330.428571
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.

Going ahead to step 13:
21 can be fit into 90 4 times, resulting in a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 35330.4285714
If we take 84 away from 90, we end up 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.

Moving on to step 14:
21 goes into 60 2 times with a remainder of 18.
Record the quotient 2 as the next digit in the result. 
Result so far: 35330.42857142
If we take 42 away from 60, we end up 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.

The final outcome is 35330.42857142, with a leftover of 1.8e-08.