We divide 506881 by 21
The aim is to understand the frequency of 21 in 506881.

Step 1:
When dividing 5 by 21, we get 0 with a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 21

On to step 2:
50 divided by 21 is 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
The remainder is 8 after subtracting 42 from 50.
Include the next digit (6) from the dividend after 8, then repeat: 86 / 21

Going ahead to step 3:
When dividing 86 by 21, we get 4 with a remainder of 2.
The next digit of our result is 4. 
Result so far: 24.0
Subtracting 84 from 86 leaves us with 2.
Take the next digit (8) from the dividend and append it to 2, then repeat: 28 / 21

Going ahead to step 4:
If we divide 28 by 21, we get 1 and a remainder of 7.
Put 1 as the next digit of the answer. 
Result so far: 241.0
The remainder is 7 after subtracting 21 from 28.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 21

Going ahead to step 5:
The number 21 fits into 78 3 times, leaving a remainder of 15.
Write down 3 as next digit of the result. 
Result so far: 2413.0
If we subtract 63 from 78, we get 15.
Fetch the next digit (1) from the dividend, attach it to 15 and continue: 151 / 21

Going ahead to step 6:
When dividing 151 by 21, we get 7 with a remainder of 4.
Write down 7 as next digit of the result. 
Result so far: 24137.0
Deduct 147 from 151 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 7:
When dividing 40 by 21, we get 1 with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 24137.1
The remainder is 19 after subtracting 21 from 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 8:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 24137.19
Subtract 189 from 190 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.

Advancing to step 9:
21 goes into 10 0 times with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 24137.19
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 10:
If we divide 100 by 21, we get 4 and a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 24137.1904
Deduct 84 from 100 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 11:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 24137.19047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 12:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 24137.190476
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Let's proceed to step 13:
When dividing 40 by 21, we get 1 with a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 24137.1904761
Subtract 21 from 40 to get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 14:
If we divide 190 by 21, we get 9 and a remainder of 1.
The next digit of our result is 9. 
Result so far: 24137.19047619
Deduct 189 from 190 and we're left 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.

The quotient of the division is 24137.19047619, and the remainder is 1e-09.