21514681 ÷ 375 
The aim is to understand the frequency of 375 in 21514681.

Advancing to step 1:
375 goes into 2 0 times with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 375

Going ahead to step 2:
The number 375 fits into 21 0 times, leaving a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Include the next digit (5) from the dividend after 21, then repeat: 215 / 375

Going ahead to step 3:
215 divided by 375 is 0 with a remainder of 215.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 215, we get 215.
Grab the next digit (1) from the dividend, add it to 215, then carry on: 2151 / 375

Moving on to step 4:
2151 divided by 375 is 5 with a remainder of 276.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
Deduct 1875 from 2151 and we're left with 276.
Append the next digit (4) from the dividend to 276 and continue with: 2764 / 375

Going ahead to step 5:
375 goes into 2764 7 times with a remainder of 139.
The next digit of our result is 7. 
Result so far: 57.0
Subtract 2625 from 2764 to get 139.
Grab the next digit (6) from the dividend, add it to 139, then carry on: 1396 / 375

Going ahead to step 6:
375 can be fit into 1396 3 times, resulting in a remainder of 271.
Use 3 as the next digit of our solution. 
Result so far: 573.0
If we take 1125 away from 1396, we end up with 271.
Fetch the next digit (8) from the dividend, attach it to 271 and continue: 2718 / 375

Going ahead to step 7:
When dividing 2718 by 375, we get 7 with a remainder of 93.
Write down 7 as next digit of the result. 
Result so far: 5737.0
Subtract 2625 from 2718 to get 93.
Include the next digit (1) from the dividend after 93, then repeat: 931 / 375

On to step 8:
375 can be fit into 931 2 times, resulting in a remainder of 181.
The next digit of our result is 2. 
Result so far: 57372.0
Deduct 750 from 931 and we're left with 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

Going ahead to step 9:
The number 375 fits into 1810 4 times, leaving a remainder of 310.
The next digit of our result is 4. 
Result so far: 57372.4
If we subtract 1500 from 1810, we get 310.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3100, and continue the process.

Moving on to step 10:
375 goes into 3100 8 times with a remainder of 100.
Use 8 as the next digit of our solution. 
Result so far: 57372.48
Subtracting 3000 from 3100 leaves us with 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

On to step 11:
When dividing 1000 by 375, we get 2 with a remainder of 250.
Record the quotient 2 as the next digit in the result. 
Result so far: 57372.482
Subtract 750 from 1000 to get 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

On to step 12:
If we divide 2500 by 375, we get 6 and a remainder of 250.
Use 6 as the next digit of our solution. 
Result so far: 57372.4826
If we subtract 2250 from 2500, we get 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

Going ahead to step 13:
When dividing 2500 by 375, we get 6 with a remainder of 250.
Put 6 as the next digit of the answer. 
Result so far: 57372.48266
Subtract 2250 from 2500 to get 250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2500, and continue the process.

After the division, we end up with 57372.48266 and a remainder of 0.00025.