We look at the division of 876773 by 77 
The aim is to understand the frequency of 77 in 876773.

On to step 1:
When dividing 8 by 77, we get 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Include the next digit (7) from the dividend after 8, then repeat: 87 / 77

Advancing to step 2:
If we divide 87 by 77, we get 1 and a remainder of 10.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 77 from 87 and we're left with 10.
Grab the next digit (6) from the dividend, add it to 10, then carry on: 106 / 77

On to step 3:
77 goes into 106 1 times with a remainder of 29.
The next digit of our result is 1. 
Result so far: 11.0
Deduct 77 from 106 and we're left with 29.
Include the next digit (7) from the dividend after 29, then repeat: 297 / 77

Let's proceed to step 4:
The number 77 fits into 297 3 times, leaving a remainder of 66.
The next digit of our result is 3. 
Result so far: 113.0
The remainder is 66 after subtracting 231 from 297.
Bring next digit (7) of the dividend behind the 66 and repeat the process: 667 / 77

On to step 5:
The number 77 fits into 667 8 times, leaving a remainder of 51.
Record the quotient 8 as the next digit in the result. 
Result so far: 1138.0
The remainder is 51 after subtracting 616 from 667.
Take the next digit (3) from the dividend and append it to 51, then repeat: 513 / 77

Advancing to step 6:
When dividing 513 by 77, we get 6 with a remainder of 51.
The number 6 becomes the next digit in our result. 
Result so far: 11386.0
Subtract 462 from 513 to get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Going ahead to step 7:
510 divided by 77 is 6 with a remainder of 48.
The number 6 becomes the next digit in our result. 
Result so far: 11386.6
The remainder is 48 after subtracting 462 from 510.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

On to step 8:
The number 77 fits into 480 6 times, leaving a remainder of 18.
Put 6 as the next digit of the answer. 
Result so far: 11386.66
The remainder is 18 after subtracting 462 from 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Our division results in 11386.66 with a remaining 0.018.