We divide 38179889 by 421
The aim is to understand the frequency of 421 in 38179889.

Advancing to step 1:
3 divided by 421 is 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Bring next digit (8) of the dividend behind the 3 and repeat the process: 38 / 421

Going ahead to step 2:
If we divide 38 by 421, we get 0 and a remainder of 38.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 38 to get 38.
Grab the next digit (1) from the dividend, add it to 38, then carry on: 381 / 421

Going ahead to step 3:
The number 421 fits into 381 0 times, leaving a remainder of 381.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 381 leaves us with 381.
Fetch the next digit (7) from the dividend, attach it to 381 and continue: 3817 / 421

On to step 4:
421 can be fit into 3817 9 times, resulting in a remainder of 28.
The next digit of our result is 9. 
Result so far: 9.0
The remainder is 28 after subtracting 3789 from 3817.
Bring next digit (9) of the dividend behind the 28 and repeat the process: 289 / 421

Advancing to step 5:
289 divided by 421 is 0 with a remainder of 289.
Use 0 as the next digit of our solution. 
Result so far: 90.0
The remainder is 289 after subtracting 0 from 289.
Fetch the next digit (8) from the dividend, attach it to 289 and continue: 2898 / 421

Moving on to step 6:
421 can be fit into 2898 6 times, resulting in a remainder of 372.
Use 6 as the next digit of our solution. 
Result so far: 906.0
If we take 2526 away from 2898, we end up with 372.
Take the next digit (8) from the dividend and append it to 372, then repeat: 3728 / 421

Advancing to step 7:
When dividing 3728 by 421, we get 8 with a remainder of 360.
The number 8 becomes the next digit in our result. 
Result so far: 9068.0
If we subtract 3368 from 3728, we get 360.
Bring next digit (9) of the dividend behind the 360 and repeat the process: 3609 / 421

Moving on to step 8:
3609 divided by 421 is 8 with a remainder of 241.
The number 8 becomes the next digit in our result. 
Result so far: 90688.0
If we take 3368 away from 3609, we end up with 241.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2410, and continue the process.

On to step 9:
421 goes into 2410 5 times with a remainder of 305.
Write down 5 as next digit of the result. 
Result so far: 90688.5
Subtracting 2105 from 2410 leaves us with 305.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

Moving on to step 10:
421 goes into 3050 7 times with a remainder of 103.
Put 7 as the next digit of the answer. 
Result so far: 90688.57
Deduct 2947 from 3050 and we're left with 103.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1030, and continue the process.

Moving on to step 11:
If we divide 1030 by 421, we get 2 and a remainder of 188.
Record the quotient 2 as the next digit in the result. 
Result so far: 90688.572
If we take 842 away from 1030, we end up with 188.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1880, and continue the process.

Going ahead to step 12:
1880 divided by 421 is 4 with a remainder of 196.
The next digit of our result is 4. 
Result so far: 90688.5724
Subtract 1684 from 1880 to get 196.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1960, and continue the process.

Let's proceed to step 13:
The number 421 fits into 1960 4 times, leaving a remainder of 276.
The number 4 becomes the next digit in our result. 
Result so far: 90688.57244
Subtract 1684 from 1960 to get 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

After the division, we end up with 90688.57244 and a remainder of 0.000276.