We look at the division of 646212 by 77 
The aim is to understand the frequency of 77 in 646212.

Step 1:
The number 77 fits into 6 0 times, leaving a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Take the next digit (4) from the dividend and append it to 6, then repeat: 64 / 77

Step 2:
77 goes into 64 0 times with a remainder of 64.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 64, we get 64.
Fetch the next digit (6) from the dividend, attach it to 64 and continue: 646 / 77

Let's proceed to step 3:
When dividing 646 by 77, we get 8 with a remainder of 30.
Use 8 as the next digit of our solution. 
Result so far: 8.0
Subtracting 616 from 646 leaves us with 30.
Fetch the next digit (2) from the dividend, attach it to 30 and continue: 302 / 77

Step 4:
The number 77 fits into 302 3 times, leaving a remainder of 71.
Write down 3 as next digit of the result. 
Result so far: 83.0
Deduct 231 from 302 and we're left with 71.
Bring next digit (1) of the dividend behind the 71 and repeat the process: 711 / 77

Moving on to step 5:
If we divide 711 by 77, we get 9 and a remainder of 18.
Put 9 as the next digit of the answer. 
Result so far: 839.0
Deduct 693 from 711 and we're left with 18.
Fetch the next digit (2) from the dividend, attach it to 18 and continue: 182 / 77

On to step 6:
If we divide 182 by 77, we get 2 and a remainder of 28.
Use 2 as the next digit of our solution. 
Result so far: 8392.0
Subtracting 154 from 182 leaves us with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Going ahead to step 7:
When dividing 280 by 77, we get 3 with a remainder of 49.
Record the quotient 3 as the next digit in the result. 
Result so far: 8392.3
Deduct 231 from 280 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Advancing to step 8:
The number 77 fits into 490 6 times, leaving a remainder of 28.
The number 6 becomes the next digit in our result. 
Result so far: 8392.36
If we take 462 away from 490, we end up with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Step 9:
If we divide 280 by 77, we get 3 and a remainder of 49.
Use 3 as the next digit of our solution. 
Result so far: 8392.363
Subtracting 231 from 280 leaves us with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Moving on to step 10:
If we divide 490 by 77, we get 6 and a remainder of 28.
Write down 6 as next digit of the result. 
Result so far: 8392.3636
Deduct 462 from 490 and we're left with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Advancing to step 11:
The number 77 fits into 280 3 times, leaving a remainder of 49.
Write down 3 as next digit of the result. 
Result so far: 8392.36363
Subtracting 231 from 280 leaves us with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Going ahead to step 12:
490 divided by 77 is 6 with a remainder of 28.
Put 6 as the next digit of the answer. 
Result so far: 8392.363636
If we subtract 462 from 490, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Advancing to step 13:
280 divided by 77 is 3 with a remainder of 49.
Write down 3 as next digit of the result. 
Result so far: 8392.3636363
Deduct 231 from 280 and we're left with 49.
Since there are no more digits in the dividend, we add a zero to the remainder making it 490, and continue the process.

Let's proceed to step 14:
490 divided by 77 is 6 with a remainder of 28.
The number 6 becomes the next digit in our result. 
Result so far: 8392.36363636
Deduct 462 from 490 and we're left with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

The final result is 8392.36363636 with a remainder of 2.8e-08.