99503852 ÷ 421 
The aim is to understand the frequency of 421 in 99503852.

Advancing to step 1:
421 goes into 9 0 times with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Include the next digit (9) from the dividend after 9, then repeat: 99 / 421

Step 2:
If we divide 99 by 421, we get 0 and a remainder of 99.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 99 leaves us with 99.
Fetch the next digit (5) from the dividend, attach it to 99 and continue: 995 / 421

Going ahead to step 3:
The number 421 fits into 995 2 times, leaving a remainder of 153.
Write down 2 as next digit of the result. 
Result so far: 2.0
If we take 842 away from 995, we end up with 153.
Include the next digit (0) from the dividend after 153, then repeat: 1530 / 421

Advancing to step 4:
1530 divided by 421 is 3 with a remainder of 267.
The next digit of our result is 3. 
Result so far: 23.0
Deduct 1263 from 1530 and we're left with 267.
Fetch the next digit (3) from the dividend, attach it to 267 and continue: 2673 / 421

Going ahead to step 5:
When dividing 2673 by 421, we get 6 with a remainder of 147.
Record the quotient 6 as the next digit in the result. 
Result so far: 236.0
Deduct 2526 from 2673 and we're left with 147.
Fetch the next digit (8) from the dividend, attach it to 147 and continue: 1478 / 421

Going ahead to step 6:
When dividing 1478 by 421, we get 3 with a remainder of 215.
Use 3 as the next digit of our solution. 
Result so far: 2363.0
Deduct 1263 from 1478 and we're left with 215.
Grab the next digit (5) from the dividend, add it to 215, then carry on: 2155 / 421

Let's proceed to step 7:
421 goes into 2155 5 times with a remainder of 50.
Record the quotient 5 as the next digit in the result. 
Result so far: 23635.0
Subtract 2105 from 2155 to get 50.
Bring next digit (2) of the dividend behind the 50 and repeat the process: 502 / 421

Moving on to step 8:
502 divided by 421 is 1 with a remainder of 81.
Use 1 as the next digit of our solution. 
Result so far: 236351.0
The remainder is 81 after subtracting 421 from 502.
Since there are no more digits in the dividend, we add a zero to the remainder making it 810, and continue the process.

Moving on to step 9:
When dividing 810 by 421, we get 1 with a remainder of 389.
The next digit of our result is 1. 
Result so far: 236351.1
Deduct 421 from 810 and we're left with 389.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3890, and continue the process.

Going ahead to step 10:
The number 421 fits into 3890 9 times, leaving a remainder of 101.
The next digit of our result is 9. 
Result so far: 236351.19
If we subtract 3789 from 3890, we get 101.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1010, and continue the process.

Let's proceed to step 11:
1010 divided by 421 is 2 with a remainder of 168.
Use 2 as the next digit of our solution. 
Result so far: 236351.192
Subtract 842 from 1010 to get 168.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1680, and continue the process.

On to step 12:
The number 421 fits into 1680 3 times, leaving a remainder of 417.
Use 3 as the next digit of our solution. 
Result so far: 236351.1923
The remainder is 417 after subtracting 1263 from 1680.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4170, and continue the process.

Moving on to step 13:
421 can be fit into 4170 9 times, resulting in a remainder of 381.
Use 9 as the next digit of our solution. 
Result so far: 236351.19239
Deduct 3789 from 4170 and we're left with 381.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3810, and continue the process.

On to step 14:
If we divide 3810 by 421, we get 9 and a remainder of 21.
Write down 9 as next digit of the result. 
Result so far: 236351.192399
Subtracting 3789 from 3810 leaves us with 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Our division results in 236351.192399 with a remaining 2.1e-06.