We're dividing 17980608 by 642 
The aim is to understand the frequency of 642 in 17980608.

Moving on to step 1:
The number 642 fits into 1 0 times, leaving a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Take the next digit (7) from the dividend and append it to 1, then repeat: 17 / 642

Advancing to step 2:
When dividing 17 by 642, we get 0 with a remainder of 17.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 17 and we're left with 17.
Take the next digit (9) from the dividend and append it to 17, then repeat: 179 / 642

Let's proceed to step 3:
642 goes into 179 0 times with a remainder of 179.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 179, we get 179.
Bring next digit (8) of the dividend behind the 179 and repeat the process: 1798 / 642

Let's proceed to step 4:
If we divide 1798 by 642, we get 2 and a remainder of 514.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtract 1284 from 1798 to get 514.
Bring next digit (0) of the dividend behind the 514 and repeat the process: 5140 / 642

Moving on to step 5:
642 can be fit into 5140 8 times, resulting in a remainder of 4.
The next digit of our result is 8. 
Result so far: 28.0
If we subtract 5136 from 5140, we get 4.
Include the next digit (6) from the dividend after 4, then repeat: 46 / 642

Advancing to step 6:
642 goes into 46 0 times with a remainder of 46.
Put 0 as the next digit of the answer. 
Result so far: 280.0
Subtract 0 from 46 to get 46.
Include the next digit (0) from the dividend after 46, then repeat: 460 / 642

Going ahead to step 7:
If we divide 460 by 642, we get 0 and a remainder of 460.
The next digit of our result is 0. 
Result so far: 2800.0
Deduct 0 from 460 and we're left with 460.
Bring next digit (8) of the dividend behind the 460 and repeat the process: 4608 / 642

Advancing to step 8:
642 goes into 4608 7 times with a remainder of 114.
Put 7 as the next digit of the answer. 
Result so far: 28007.0
Subtract 4494 from 4608 to get 114.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1140, and continue the process.

Advancing to step 9:
If we divide 1140 by 642, we get 1 and a remainder of 498.
The next digit of our result is 1. 
Result so far: 28007.1
If we take 642 away from 1140, we end up with 498.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Going ahead to step 10:
4980 divided by 642 is 7 with a remainder of 486.
Write down 7 as next digit of the result. 
Result so far: 28007.17
Subtract 4494 from 4980 to get 486.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4860, and continue the process.

Going ahead to step 11:
When dividing 4860 by 642, we get 7 with a remainder of 366.
The number 7 becomes the next digit in our result. 
Result so far: 28007.177
Subtracting 4494 from 4860 leaves us with 366.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3660, and continue the process.

After the division, we end up with 28007.177 and a remainder of 0.0366.