520294 divided by 21 
The aim is to understand the frequency of 21 in 520294.

Let's proceed to step 1:
21 can be fit into 5 0 times, resulting in a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Grab the next digit (2) from the dividend, add it to 5, then carry on: 52 / 21

Let's proceed to step 2:
21 goes into 52 2 times with a remainder of 10.
Use 2 as the next digit of our solution. 
Result so far: 2.0
The remainder is 10 after subtracting 42 from 52.
Append the next digit (0) from the dividend to 10 and continue with: 100 / 21

Moving on to step 3:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 24.0
If we take 84 away from 100, we end up with 16.
Bring next digit (2) of the dividend behind the 16 and repeat the process: 162 / 21

Step 4:
When dividing 162 by 21, we get 7 with a remainder of 15.
The next digit of our result is 7. 
Result so far: 247.0
If we take 147 away from 162, we end up with 15.
Bring next digit (9) of the dividend behind the 15 and repeat the process: 159 / 21

Moving on to step 5:
21 goes into 159 7 times with a remainder of 12.
The number 7 becomes the next digit in our result. 
Result so far: 2477.0
The remainder is 12 after subtracting 147 from 159.
Grab the next digit (4) from the dividend, add it to 12, then carry on: 124 / 21

Let's proceed to step 6:
The number 21 fits into 124 5 times, leaving a remainder of 19.
Write down 5 as next digit of the result. 
Result so far: 24775.0
If we subtract 105 from 124, we 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.

On to step 7:
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: 24775.9
If we subtract 189 from 190, we 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.

Let's proceed to step 8:
If we divide 10 by 21, we get 0 and a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 24775.9
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 9:
When dividing 100 by 21, we get 4 with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 24775.904
Subtracting 84 from 100 leaves us 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.

On to step 10:
If we divide 160 by 21, we get 7 and a remainder of 13.
The next digit of our result is 7. 
Result so far: 24775.9047
Subtract 147 from 160 to 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.

Advancing to step 11:
If we divide 130 by 21, we get 6 and a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 24775.90476
Subtracting 126 from 130 leaves us 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.

Moving on to step 12:
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: 24775.904761
If we take 21 away from 40, we end up with 19.
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 13:
If we divide 190 by 21, we get 9 and a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 24775.9047619
If we take 189 away from 190, 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 14:
When dividing 10 by 21, we get 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 24775.9047619
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.

The quotient of the division is 24775.9047619, and the remainder is 1e-08.