57726310 ÷ 421 
The aim is to understand the frequency of 421 in 57726310.

Step 1:
5 divided by 421 is 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Grab the next digit (7) from the dividend, add it to 5, then carry on: 57 / 421

Let's proceed to step 2:
If we divide 57 by 421, we get 0 and a remainder of 57.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 57, we get 57.
Include the next digit (7) from the dividend after 57, then repeat: 577 / 421

On to step 3:
421 goes into 577 1 times with a remainder of 156.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 156 after subtracting 421 from 577.
Grab the next digit (2) from the dividend, add it to 156, then carry on: 1562 / 421

On to step 4:
1562 divided by 421 is 3 with a remainder of 299.
Write down 3 as next digit of the result. 
Result so far: 13.0
Subtracting 1263 from 1562 leaves us with 299.
Bring next digit (6) of the dividend behind the 299 and repeat the process: 2996 / 421

Moving on to step 5:
421 can be fit into 2996 7 times, resulting in a remainder of 49.
Put 7 as the next digit of the answer. 
Result so far: 137.0
The remainder is 49 after subtracting 2947 from 2996.
Fetch the next digit (3) from the dividend, attach it to 49 and continue: 493 / 421

On to step 6:
421 can be fit into 493 1 times, resulting in a remainder of 72.
Put 1 as the next digit of the answer. 
Result so far: 1371.0
If we subtract 421 from 493, we get 72.
Take the next digit (1) from the dividend and append it to 72, then repeat: 721 / 421

On to step 7:
421 goes into 721 1 times with a remainder of 300.
The next digit of our result is 1. 
Result so far: 13711.0
If we take 421 away from 721, we end up with 300.
Take the next digit (0) from the dividend and append it to 300, then repeat: 3000 / 421

Let's proceed to step 8:
The number 421 fits into 3000 7 times, leaving a remainder of 53.
Use 7 as the next digit of our solution. 
Result so far: 137117.0
Subtract 2947 from 3000 to get 53.
Since there are no more digits in the dividend, we add a zero to the remainder making it 530, and continue the process.

Going ahead to step 9:
The number 421 fits into 530 1 times, leaving a remainder of 109.
Write down 1 as next digit of the result. 
Result so far: 137117.1
If we subtract 421 from 530, we get 109.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1090, and continue the process.

Moving on to step 10:
If we divide 1090 by 421, we get 2 and a remainder of 248.
Record the quotient 2 as the next digit in the result. 
Result so far: 137117.12
Subtract 842 from 1090 to get 248.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2480, and continue the process.

On to step 11:
The number 421 fits into 2480 5 times, leaving a remainder of 375.
The number 5 becomes the next digit in our result. 
Result so far: 137117.125
Deduct 2105 from 2480 and we're left with 375.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3750, and continue the process.

Let's proceed to step 12:
421 goes into 3750 8 times with a remainder of 382.
Record the quotient 8 as the next digit in the result. 
Result so far: 137117.1258
If we take 3368 away from 3750, we end up with 382.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3820, and continue the process.

Moving on to step 13:
If we divide 3820 by 421, we get 9 and a remainder of 31.
Put 9 as the next digit of the answer. 
Result so far: 137117.12589
The remainder is 31 after subtracting 3789 from 3820.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Step 14:
421 can be fit into 310 0 times, resulting in a remainder of 310.
Put 0 as the next digit of the answer. 
Result so far: 137117.12589
Deduct 0 from 310 and we're left with 310.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3100, and continue the process.

Advancing to step 15:
The number 421 fits into 3100 7 times, leaving a remainder of 153.
The next digit of our result is 7. 
Result so far: 137117.1258907
Subtract 2947 from 3100 to get 153.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1530, and continue the process.

Let's proceed to step 16:
1530 divided by 421 is 3 with a remainder of 267.
The number 3 becomes the next digit in our result. 
Result so far: 137117.12589073
Subtracting 1263 from 1530 leaves us with 267.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2670, and continue the process.

The final outcome is 137117.12589073, with a leftover of 2.67e-07.