We look at the division of 10721099 by 77 
The aim is to understand the frequency of 77 in 10721099.

On to step 1:
77 can be fit into 1 0 times, resulting in a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Append the next digit (0) from the dividend to 1 and continue with: 10 / 77

Advancing to step 2:
When dividing 10 by 77, we get 0 with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 10 to get 10.
Append the next digit (7) from the dividend to 10 and continue with: 107 / 77

Moving on to step 3:
The number 77 fits into 107 1 times, leaving a remainder of 30.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 77 from 107 and we're left with 30.
Fetch the next digit (2) from the dividend, attach it to 30 and continue: 302 / 77

On to step 4:
77 goes into 302 3 times with a remainder of 71.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
The remainder is 71 after subtracting 231 from 302.
Bring next digit (1) of the dividend behind the 71 and repeat the process: 711 / 77

Moving on to step 5:
The number 77 fits into 711 9 times, leaving a remainder of 18.
The number 9 becomes the next digit in our result. 
Result so far: 139.0
The remainder is 18 after subtracting 693 from 711.
Bring next digit (0) of the dividend behind the 18 and repeat the process: 180 / 77

Let's proceed to step 6:
180 divided by 77 is 2 with a remainder of 26.
Write down 2 as next digit of the result. 
Result so far: 1392.0
Subtract 154 from 180 to get 26.
Bring next digit (9) of the dividend behind the 26 and repeat the process: 269 / 77

Advancing to step 7:
77 can be fit into 269 3 times, resulting in a remainder of 38.
Record the quotient 3 as the next digit in the result. 
Result so far: 13923.0
The remainder is 38 after subtracting 231 from 269.
Grab the next digit (9) from the dividend, add it to 38, then carry on: 389 / 77

Step 8:
When dividing 389 by 77, we get 5 with a remainder of 4.
Write down 5 as next digit of the result. 
Result so far: 139235.0
The remainder is 4 after subtracting 385 from 389.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 9:
77 goes into 40 0 times with a remainder of 40.
Use 0 as the next digit of our solution. 
Result so far: 139235.0
The remainder is 40 after subtracting 0 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Step 10:
77 goes into 400 5 times with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 139235.05
Deduct 385 from 400 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 11:
When dividing 150 by 77, we get 1 with a remainder of 73.
Put 1 as the next digit of the answer. 
Result so far: 139235.051
Deduct 77 from 150 and we're left with 73.
Since there are no more digits in the dividend, we add a zero to the remainder making it 730, and continue the process.

Step 12:
77 can be fit into 730 9 times, resulting in a remainder of 37.
The number 9 becomes the next digit in our result. 
Result so far: 139235.0519
Subtract 693 from 730 to get 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Advancing to step 13:
The number 77 fits into 370 4 times, leaving a remainder of 62.
Record the quotient 4 as the next digit in the result. 
Result so far: 139235.05194
Subtract 308 from 370 to get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 14:
77 can be fit into 620 8 times, resulting in a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 139235.051948
If we subtract 616 from 620, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 15:
40 divided by 77 is 0 with a remainder of 40.
The next digit of our result is 0. 
Result so far: 139235.051948
If we subtract 0 from 40, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 16:
If we divide 400 by 77, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 139235.05194805
If we take 385 away from 400, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

The final result is 139235.05194805 with a remainder of 1.5e-08.