We're dividing 873322 by 21 
The aim is to understand the frequency of 21 in 873322.

Step 1:
21 can be fit into 8 0 times, resulting in a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (7) from the dividend and append it to 8, then repeat: 87 / 21

Moving on to step 2:
87 divided by 21 is 4 with a remainder of 3.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we subtract 84 from 87, we get 3.
Include the next digit (3) from the dividend after 3, then repeat: 33 / 21

Going ahead to step 3:
When dividing 33 by 21, we get 1 with a remainder of 12.
Put 1 as the next digit of the answer. 
Result so far: 41.0
If we subtract 21 from 33, we get 12.
Grab the next digit (3) from the dividend, add it to 12, then carry on: 123 / 21

On to step 4:
When dividing 123 by 21, we get 5 with a remainder of 18.
The number 5 becomes the next digit in our result. 
Result so far: 415.0
If we subtract 105 from 123, we get 18.
Take the next digit (2) from the dividend and append it to 18, then repeat: 182 / 21

Moving on to step 5:
If we divide 182 by 21, we get 8 and a remainder of 14.
The number 8 becomes the next digit in our result. 
Result so far: 4158.0
Subtract 168 from 182 to get 14.
Append the next digit (2) from the dividend to 14 and continue with: 142 / 21

Moving on to step 6:
If we divide 142 by 21, we get 6 and a remainder of 16.
Record the quotient 6 as the next digit in the result. 
Result so far: 41586.0
The remainder is 16 after subtracting 126 from 142.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 7:
160 divided by 21 is 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 41586.7
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Step 8:
When dividing 130 by 21, we get 6 with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 41586.76
If we subtract 126 from 130, we get 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 9:
40 divided by 21 is 1 with a remainder of 19.
Record the quotient 1 as the next digit in the result. 
Result so far: 41586.761
Deduct 21 from 40 and we're left 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.

Moving on to step 10:
The number 21 fits into 190 9 times, leaving a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 41586.7619
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.

Advancing to step 11:
If we divide 10 by 21, we get 0 and a remainder of 10.
The next digit of our result is 0. 
Result so far: 41586.7619
Deduct 0 from 10 and we're left 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 12:
The number 21 fits into 100 4 times, leaving a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 41586.761904
If we take 84 away from 100, we end up 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 13:
21 goes into 160 7 times with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 41586.7619047
If we take 147 away from 160, we end up with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 14:
When dividing 130 by 21, we get 6 with a remainder of 4.
The number 6 becomes the next digit in our result. 
Result so far: 41586.76190476
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The quotient of the division is 41586.76190476, and the remainder is 4e-09.