We're dividing 42573 by 77 
The aim is to understand the frequency of 77 in 42573.

On to step 1:
When dividing 4 by 77, we get 0 with a remainder of 4.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 4 to get 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 77

Advancing to step 2:
If we divide 42 by 77, we get 0 and a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 42 to get 42.
Bring next digit (5) of the dividend behind the 42 and repeat the process: 425 / 77

Advancing to step 3:
77 can be fit into 425 5 times, resulting in a remainder of 40.
Write down 5 as next digit of the result. 
Result so far: 5.0
Subtract 385 from 425 to get 40.
Grab the next digit (7) from the dividend, add it to 40, then carry on: 407 / 77

Advancing to step 4:
407 divided by 77 is 5 with a remainder of 22.
Put 5 as the next digit of the answer. 
Result so far: 55.0
Deduct 385 from 407 and we're left with 22.
Bring next digit (3) of the dividend behind the 22 and repeat the process: 223 / 77

Advancing to step 5:
223 divided by 77 is 2 with a remainder of 69.
Use 2 as the next digit of our solution. 
Result so far: 552.0
Subtracting 154 from 223 leaves us with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

On to step 6:
77 can be fit into 690 8 times, resulting in a remainder of 74.
Record the quotient 8 as the next digit in the result. 
Result so far: 552.8
Deduct 616 from 690 and we're left with 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

On to step 7:
77 can be fit into 740 9 times, resulting in a remainder of 47.
Write down 9 as next digit of the result. 
Result so far: 552.89
Subtract 693 from 740 to get 47.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

Step 8:
If we divide 470 by 77, we get 6 and a remainder of 8.
Use 6 as the next digit of our solution. 
Result so far: 552.896
If we subtract 462 from 470, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 9:
The number 77 fits into 80 1 times, leaving a remainder of 3.
Write down 1 as next digit of the result. 
Result so far: 552.8961
If we subtract 77 from 80, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 10:
When dividing 30 by 77, we get 0 with a remainder of 30.
The number 0 becomes the next digit in our result. 
Result so far: 552.8961
Subtracting 0 from 30 leaves us with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

On to step 11:
If we divide 300 by 77, we get 3 and a remainder of 69.
Record the quotient 3 as the next digit in the result. 
Result so far: 552.896103
Deduct 231 from 300 and we're left with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Going ahead to step 12:
690 divided by 77 is 8 with a remainder of 74.
Use 8 as the next digit of our solution. 
Result so far: 552.8961038
If we take 616 away from 690, we end up with 74.
Since there are no more digits in the dividend, we add a zero to the remainder making it 740, and continue the process.

Advancing to step 13:
77 can be fit into 740 9 times, resulting in a remainder of 47.
The number 9 becomes the next digit in our result. 
Result so far: 552.89610389
Subtract 693 from 740 to get 47.
Since there are no more digits in the dividend, we add a zero to the remainder making it 470, and continue the process.

The final result is 552.89610389 with a remainder of 4.7e-08.