We look at the division of 217311 by 77 
The aim is to understand the frequency of 77 in 217311.

Going ahead to step 1:
The number 77 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 77

Step 2:
When dividing 21 by 77, we get 0 with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Take the next digit (7) from the dividend and append it to 21, then repeat: 217 / 77

Advancing to step 3:
The number 77 fits into 217 2 times, leaving a remainder of 63.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we take 154 away from 217, we end up with 63.
Include the next digit (3) from the dividend after 63, then repeat: 633 / 77

Moving on to step 4:
The number 77 fits into 633 8 times, leaving a remainder of 17.
Record the quotient 8 as the next digit in the result. 
Result so far: 28.0
If we subtract 616 from 633, we get 17.
Append the next digit (1) from the dividend to 17 and continue with: 171 / 77

Moving on to step 5:
77 can be fit into 171 2 times, resulting in a remainder of 17.
Put 2 as the next digit of the answer. 
Result so far: 282.0
If we subtract 154 from 171, we get 17.
Append the next digit (1) from the dividend to 17 and continue with: 171 / 77

On to step 6:
171 divided by 77 is 2 with a remainder of 17.
Record the quotient 2 as the next digit in the result. 
Result so far: 2822.0
Deduct 154 from 171 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 7:
If we divide 170 by 77, we get 2 and a remainder of 16.
Write down 2 as next digit of the result. 
Result so far: 2822.2
If we take 154 away from 170, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 8:
77 goes into 160 2 times with a remainder of 6.
Use 2 as the next digit of our solution. 
Result so far: 2822.22
If we take 154 away from 160, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The final result is 2822.22 with a remainder of 0.006.