We're dividing 90915077 by 721 
The aim is to understand the frequency of 721 in 90915077.

On to step 1:
721 can be fit into 9 0 times, resulting in a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Take the next digit (0) from the dividend and append it to 9, then repeat: 90 / 721

Moving on to step 2:
721 can be fit into 90 0 times, resulting in a remainder of 90.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 90, we get 90.
Bring next digit (9) of the dividend behind the 90 and repeat the process: 909 / 721

Advancing to step 3:
When dividing 909 by 721, we get 1 with a remainder of 188.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we subtract 721 from 909, we get 188.
Fetch the next digit (1) from the dividend, attach it to 188 and continue: 1881 / 721

Step 4:
721 can be fit into 1881 2 times, resulting in a remainder of 439.
Put 2 as the next digit of the answer. 
Result so far: 12.0
Subtracting 1442 from 1881 leaves us with 439.
Bring next digit (5) of the dividend behind the 439 and repeat the process: 4395 / 721

Going ahead to step 5:
4395 divided by 721 is 6 with a remainder of 69.
Record the quotient 6 as the next digit in the result. 
Result so far: 126.0
Deduct 4326 from 4395 and we're left with 69.
Fetch the next digit (0) from the dividend, attach it to 69 and continue: 690 / 721

Going ahead to step 6:
721 can be fit into 690 0 times, resulting in a remainder of 690.
Record the quotient 0 as the next digit in the result. 
Result so far: 1260.0
Subtract 0 from 690 to get 690.
Append the next digit (7) from the dividend to 690 and continue with: 6907 / 721

Moving on to step 7:
721 goes into 6907 9 times with a remainder of 418.
The number 9 becomes the next digit in our result. 
Result so far: 12609.0
If we take 6489 away from 6907, we end up with 418.
Include the next digit (7) from the dividend after 418, then repeat: 4187 / 721

Let's proceed to step 8:
The number 721 fits into 4187 5 times, leaving a remainder of 582.
The next digit of our result is 5. 
Result so far: 126095.0
The remainder is 582 after subtracting 3605 from 4187.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5820, and continue the process.

Going ahead to step 9:
721 goes into 5820 8 times with a remainder of 52.
Record the quotient 8 as the next digit in the result. 
Result so far: 126095.8
Subtract 5768 from 5820 to get 52.
Since there are no more digits in the dividend, we add a zero to the remainder making it 520, and continue the process.

Moving on to step 10:
721 can be fit into 520 0 times, resulting in a remainder of 520.
Use 0 as the next digit of our solution. 
Result so far: 126095.8
Subtract 0 from 520 to get 520.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5200, and continue the process.

Going ahead to step 11:
721 can be fit into 5200 7 times, resulting in a remainder of 153.
Write down 7 as next digit of the result. 
Result so far: 126095.807
Subtracting 5047 from 5200 leaves us with 153.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1530, and continue the process.

Advancing to step 12:
The number 721 fits into 1530 2 times, leaving a remainder of 88.
Write down 2 as next digit of the result. 
Result so far: 126095.8072
Subtract 1442 from 1530 to get 88.
Since there are no more digits in the dividend, we add a zero to the remainder making it 880, and continue the process.

On to step 13:
If we divide 880 by 721, we get 1 and a remainder of 159.
Put 1 as the next digit of the answer. 
Result so far: 126095.80721
Deduct 721 from 880 and we're left with 159.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1590, and continue the process.

On to step 14:
721 goes into 1590 2 times with a remainder of 148.
Write down 2 as next digit of the result. 
Result so far: 126095.807212
If we subtract 1442 from 1590, we get 148.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1480, and continue the process.

Going ahead to step 15:
721 goes into 1480 2 times with a remainder of 38.
Record the quotient 2 as the next digit in the result. 
Result so far: 126095.8072122
Deduct 1442 from 1480 and we're left with 38.
Since there are no more digits in the dividend, we add a zero to the remainder making it 380, and continue the process.

After the division, we end up with 126095.8072122 and a remainder of 3.8e-07.