We look at the division of 821891 by 2 
The aim is to understand the frequency of 2 in 821891.

Moving on to step 1:
The number 2 fits into 8 4 times, leaving a remainder of 0.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Subtract 8 from 8 to get 0.
Grab the next digit (2) from the dividend, add it to 0, then carry on: 2 / 2

Moving on to step 2:
If we divide 2 by 2, we get 1 and a remainder of 0.
The next digit of our result is 1. 
Result so far: 41.0
If we subtract 2 from 2, we get 0.
Fetch the next digit (1) from the dividend, attach it to 0 and continue: 1 / 2

On to step 3:
The number 2 fits into 1 0 times, leaving a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 410.0
The remainder is 1 after subtracting 0 from 1.
Take the next digit (8) from the dividend and append it to 1, then repeat: 18 / 2

Advancing to step 4:
2 can be fit into 18 9 times, resulting in a remainder of 0.
The next digit of our result is 9. 
Result so far: 4109.0
The remainder is 0 after subtracting 18 from 18.
Take the next digit (9) from the dividend and append it to 0, then repeat: 9 / 2

On to step 5:
The number 2 fits into 9 4 times, leaving a remainder of 1.
Use 4 as the next digit of our solution. 
Result so far: 41094.0
Deduct 8 from 9 and we're left with 1.
Append the next digit (1) from the dividend to 1 and continue with: 11 / 2

Advancing to step 6:
If we divide 11 by 2, we get 5 and a remainder of 1.
Record the quotient 5 as the next digit in the result. 
Result so far: 410945.0
Subtract 10 from 11 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 7:
2 can be fit into 10 5 times, resulting in a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 410945.5
Deduct 10 from 10 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
0 divided by 2 is 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 410945.5
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 9:
0 divided by 2 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 410945.5
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 410945.5 and a remainder of 0.0.