We divide 21019 by 2
The aim is to understand the frequency of 2 in 21019.

On to step 1:
2 can be fit into 2 1 times, resulting in a remainder of 0.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 2 from 2 leaves us with 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 2

On to step 2:
When dividing 1 by 2, we get 0 with a remainder of 1.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
If we take 0 away from 1, we end up with 1.
Bring next digit (0) of the dividend behind the 1 and repeat the process: 10 / 2

On to step 3:
If we divide 10 by 2, we get 5 and a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 105.0
Subtracting 10 from 10 leaves us with 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 2

Step 4:
2 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 1050.0
Deduct 0 from 1 and we're left with 1.
Include the next digit (9) from the dividend after 1, then repeat: 19 / 2

On to step 5:
2 goes into 19 9 times with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 10509.0
If we take 18 away from 19, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Step 6:
2 goes into 10 5 times with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 10509.5
Subtract 10 from 10 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.

Moving on to step 7:
The number 2 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 10509.5
If we take 0 away from 0, we end up 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.

Step 8:
When dividing 0 by 2, we get 0 with a remainder of 0.
The next digit of our result is 0. 
Result so far: 10509.5
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.

The final result is 10509.5 with a remainder of 0.0.