55775835 divided by 21 
The aim is to understand the frequency of 21 in 55775835.

Let's proceed to step 1:
5 divided by 21 is 0 with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Bring next digit (5) of the dividend behind the 5 and repeat the process: 55 / 21

Step 2:
If we divide 55 by 21, we get 2 and a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 2.0
Subtract 42 from 55 to get 13.
Take the next digit (7) from the dividend and append it to 13, then repeat: 137 / 21

Step 3:
When dividing 137 by 21, we get 6 with a remainder of 11.
The number 6 becomes the next digit in our result. 
Result so far: 26.0
Subtract 126 from 137 to get 11.
Grab the next digit (7) from the dividend, add it to 11, then carry on: 117 / 21

Advancing to step 4:
If we divide 117 by 21, we get 5 and a remainder of 12.
Record the quotient 5 as the next digit in the result. 
Result so far: 265.0
Subtract 105 from 117 to get 12.
Take the next digit (5) from the dividend and append it to 12, then repeat: 125 / 21

Going ahead to step 5:
21 goes into 125 5 times with a remainder of 20.
Use 5 as the next digit of our solution. 
Result so far: 2655.0
If we take 105 away from 125, we end up with 20.
Include the next digit (8) from the dividend after 20, then repeat: 208 / 21

On to step 6:
If we divide 208 by 21, we get 9 and a remainder of 19.
Put 9 as the next digit of the answer. 
Result so far: 26559.0
Subtracting 189 from 208 leaves us with 19.
Append the next digit (3) from the dividend to 19 and continue with: 193 / 21

Moving on to step 7:
21 can be fit into 193 9 times, resulting in a remainder of 4.
Use 9 as the next digit of our solution. 
Result so far: 265599.0
Subtracting 189 from 193 leaves us with 4.
Fetch the next digit (5) from the dividend, attach it to 4 and continue: 45 / 21

On to step 8:
When dividing 45 by 21, we get 2 with a remainder of 3.
The next digit of our result is 2. 
Result so far: 2655992.0
Deduct 42 from 45 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 9:
If we divide 30 by 21, we get 1 and a remainder of 9.
The next digit of our result is 1. 
Result so far: 2655992.1
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 10:
21 goes into 90 4 times with a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 2655992.14
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 11:
60 divided by 21 is 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 2655992.142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 12:
21 goes into 180 8 times with a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 2655992.1428
Subtract 168 from 180 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 13:
If we divide 120 by 21, we get 5 and a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 2655992.14285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 14:
The number 21 fits into 150 7 times, leaving a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 2655992.142857
Subtract 147 from 150 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 15:
When dividing 30 by 21, we get 1 with a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 2655992.1428571
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 16:
21 goes into 90 4 times with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 2655992.14285714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Our division results in 2655992.14285714 with a remaining 6e-09.