599558 ÷ 21 
The aim is to understand the frequency of 21 in 599558.

Let's proceed to step 1:
If we divide 5 by 21, we get 0 and a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Bring next digit (9) of the dividend behind the 5 and repeat the process: 59 / 21

Let's proceed to step 2:
59 divided by 21 is 2 with a remainder of 17.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
The remainder is 17 after subtracting 42 from 59.
Append the next digit (9) from the dividend to 17 and continue with: 179 / 21

Let's proceed to step 3:
If we divide 179 by 21, we get 8 and a remainder of 11.
Put 8 as the next digit of the answer. 
Result so far: 28.0
Subtracting 168 from 179 leaves us with 11.
Fetch the next digit (5) from the dividend, attach it to 11 and continue: 115 / 21

Moving on to step 4:
21 goes into 115 5 times with a remainder of 10.
Write down 5 as next digit of the result. 
Result so far: 285.0
If we subtract 105 from 115, we get 10.
Include the next digit (5) from the dividend after 10, then repeat: 105 / 21

Step 5:
If we divide 105 by 21, we get 5 and a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 2855.0
Subtract 105 from 105 to get 0.
Take the next digit (8) from the dividend and append it to 0, then repeat: 8 / 21

Going ahead to step 6:
21 goes into 8 0 times with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 28550.0
If we subtract 0 from 8, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 7:
21 goes into 80 3 times with a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 28550.3
If we take 63 away from 80, we end up with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 8:
When dividing 170 by 21, we get 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 28550.38
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 9:
When dividing 20 by 21, we get 0 with a remainder of 20.
The next digit of our result is 0. 
Result so far: 28550.38
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

On to step 10:
If we divide 200 by 21, we get 9 and a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 28550.3809
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 11:
21 can be fit into 110 5 times, resulting in a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 28550.38095
If we take 105 away from 110, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 12:
If we divide 50 by 21, we get 2 and a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 28550.380952
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Advancing to step 13:
When dividing 80 by 21, we get 3 with a remainder of 17.
Use 3 as the next digit of our solution. 
Result so far: 28550.3809523
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Step 14:
If we divide 170 by 21, we get 8 and a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 28550.38095238
The remainder is 2 after subtracting 168 from 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The quotient of the division is 28550.38095238, and the remainder is 2e-09.