744310 divided by 21 
The aim is to understand the frequency of 21 in 744310.

Moving on to step 1:
21 goes into 7 0 times with a remainder of 7.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Bring next digit (4) of the dividend behind the 7 and repeat the process: 74 / 21

Let's proceed to step 2:
The number 21 fits into 74 3 times, leaving a remainder of 11.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtracting 63 from 74 leaves us with 11.
Fetch the next digit (4) from the dividend, attach it to 11 and continue: 114 / 21

Moving on to step 3:
114 divided by 21 is 5 with a remainder of 9.
Write down 5 as next digit of the result. 
Result so far: 35.0
The remainder is 9 after subtracting 105 from 114.
Bring next digit (3) of the dividend behind the 9 and repeat the process: 93 / 21

Advancing to step 4:
21 can be fit into 93 4 times, resulting in a remainder of 9.
Put 4 as the next digit of the answer. 
Result so far: 354.0
Deduct 84 from 93 and we're left with 9.
Append the next digit (1) from the dividend to 9 and continue with: 91 / 21

Going ahead to step 5:
91 divided by 21 is 4 with a remainder of 7.
The next digit of our result is 4. 
Result so far: 3544.0
If we take 84 away from 91, we end up with 7.
Fetch the next digit (0) from the dividend, attach it to 7 and continue: 70 / 21

Let's proceed to step 6:
21 can be fit into 70 3 times, resulting in a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 35443.0
Subtracting 63 from 70 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 7:
21 can be fit into 70 3 times, resulting in a remainder of 7.
The next digit of our result is 3. 
Result so far: 35443.3
Deduct 63 from 70 and we're left with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 8:
21 goes into 70 3 times with a remainder of 7.
Record the quotient 3 as the next digit in the result. 
Result so far: 35443.33
Subtract 63 from 70 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final outcome is 35443.33, with a leftover of 0.007.