Let's divide 28100214 by 645
The aim is to understand the frequency of 645 in 28100214.

Moving on to step 1:
The number 645 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Bring next digit (8) of the dividend behind the 2 and repeat the process: 28 / 645

Step 2:
If we divide 28 by 645, we get 0 and a remainder of 28.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 28 after subtracting 0 from 28.
Append the next digit (1) from the dividend to 28 and continue with: 281 / 645

Step 3:
281 divided by 645 is 0 with a remainder of 281.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 281 to get 281.
Bring next digit (0) of the dividend behind the 281 and repeat the process: 2810 / 645

Moving on to step 4:
645 can be fit into 2810 4 times, resulting in a remainder of 230.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we take 2580 away from 2810, we end up with 230.
Bring next digit (0) of the dividend behind the 230 and repeat the process: 2300 / 645

On to step 5:
2300 divided by 645 is 3 with a remainder of 365.
Use 3 as the next digit of our solution. 
Result so far: 43.0
Subtracting 1935 from 2300 leaves us with 365.
Include the next digit (2) from the dividend after 365, then repeat: 3652 / 645

On to step 6:
3652 divided by 645 is 5 with a remainder of 427.
Record the quotient 5 as the next digit in the result. 
Result so far: 435.0
Subtracting 3225 from 3652 leaves us with 427.
Append the next digit (1) from the dividend to 427 and continue with: 4271 / 645

On to step 7:
4271 divided by 645 is 6 with a remainder of 401.
The next digit of our result is 6. 
Result so far: 4356.0
The remainder is 401 after subtracting 3870 from 4271.
Append the next digit (4) from the dividend to 401 and continue with: 4014 / 645

On to step 8:
645 goes into 4014 6 times with a remainder of 144.
Put 6 as the next digit of the answer. 
Result so far: 43566.0
If we take 3870 away from 4014, we end up with 144.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1440, and continue the process.

Let's proceed to step 9:
645 goes into 1440 2 times with a remainder of 150.
Write down 2 as next digit of the result. 
Result so far: 43566.2
If we subtract 1290 from 1440, we get 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

On to step 10:
When dividing 1500 by 645, we get 2 with a remainder of 210.
Write down 2 as next digit of the result. 
Result so far: 43566.22
The remainder is 210 after subtracting 1290 from 1500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2100, and continue the process.

The final outcome is 43566.22, with a leftover of 0.21.