We look at the division of 81888018 by 210 
The aim is to understand the frequency of 210 in 81888018.

Let's proceed to step 1:
When dividing 8 by 210, we get 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 210

Going ahead to step 2:
81 divided by 210 is 0 with a remainder of 81.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 81 to get 81.
Include the next digit (8) from the dividend after 81, then repeat: 818 / 210

Moving on to step 3:
210 can be fit into 818 3 times, resulting in a remainder of 188.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we subtract 630 from 818, we get 188.
Take the next digit (8) from the dividend and append it to 188, then repeat: 1888 / 210

Step 4:
If we divide 1888 by 210, we get 8 and a remainder of 208.
Use 8 as the next digit of our solution. 
Result so far: 38.0
Deduct 1680 from 1888 and we're left with 208.
Bring next digit (8) of the dividend behind the 208 and repeat the process: 2088 / 210

Let's proceed to step 5:
210 goes into 2088 9 times with a remainder of 198.
Put 9 as the next digit of the answer. 
Result so far: 389.0
If we subtract 1890 from 2088, we get 198.
Bring next digit (0) of the dividend behind the 198 and repeat the process: 1980 / 210

Going ahead to step 6:
When dividing 1980 by 210, we get 9 with a remainder of 90.
Use 9 as the next digit of our solution. 
Result so far: 3899.0
Subtract 1890 from 1980 to get 90.
Include the next digit (1) from the dividend after 90, then repeat: 901 / 210

Going ahead to step 7:
The number 210 fits into 901 4 times, leaving a remainder of 61.
The number 4 becomes the next digit in our result. 
Result so far: 38994.0
If we take 840 away from 901, we end up with 61.
Include the next digit (8) from the dividend after 61, then repeat: 618 / 210

Going ahead to step 8:
When dividing 618 by 210, we get 2 with a remainder of 198.
Use 2 as the next digit of our solution. 
Result so far: 389942.0
Deduct 420 from 618 and we're left with 198.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1980, and continue the process.

Step 9:
210 goes into 1980 9 times with a remainder of 90.
Put 9 as the next digit of the answer. 
Result so far: 389942.9
If we take 1890 away from 1980, we end up with 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Moving on to step 10:
The number 210 fits into 900 4 times, leaving a remainder of 60.
The number 4 becomes the next digit in our result. 
Result so far: 389942.94
The remainder is 60 after subtracting 840 from 900.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 11:
600 divided by 210 is 2 with a remainder of 180.
The number 2 becomes the next digit in our result. 
Result so far: 389942.942
If we subtract 420 from 600, we get 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Let's proceed to step 12:
210 goes into 1800 8 times with a remainder of 120.
Use 8 as the next digit of our solution. 
Result so far: 389942.9428
If we take 1680 away from 1800, we end up with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 13:
The number 210 fits into 1200 5 times, leaving a remainder of 150.
Put 5 as the next digit of the answer. 
Result so far: 389942.94285
Deduct 1050 from 1200 and we're left with 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Step 14:
If we divide 1500 by 210, we get 7 and a remainder of 30.
The next digit of our result is 7. 
Result so far: 389942.942857
Deduct 1470 from 1500 and we're left 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.

Step 15:
The number 210 fits into 300 1 times, leaving a remainder of 90.
Write down 1 as next digit of the result. 
Result so far: 389942.9428571
The remainder is 90 after subtracting 210 from 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 900, and continue the process.

Moving on to step 16:
When dividing 900 by 210, we get 4 with a remainder of 60.
The number 4 becomes the next digit in our result. 
Result so far: 389942.94285714
If we take 840 away from 900, we end up with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

The final result is 389942.94285714 with a remainder of 6e-08.