Let's divide 878629 by 21
The aim is to understand the frequency of 21 in 878629.

Let's proceed to step 1:
The number 21 fits into 8 0 times, leaving a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Append the next digit (7) from the dividend to 8 and continue with: 87 / 21

Going ahead to step 2:
21 can be fit into 87 4 times, resulting in a remainder of 3.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
If we subtract 84 from 87, we get 3.
Append the next digit (8) from the dividend to 3 and continue with: 38 / 21

Let's proceed to step 3:
When dividing 38 by 21, we get 1 with a remainder of 17.
The number 1 becomes the next digit in our result. 
Result so far: 41.0
The remainder is 17 after subtracting 21 from 38.
Include the next digit (6) from the dividend after 17, then repeat: 176 / 21

Step 4:
If we divide 176 by 21, we get 8 and a remainder of 8.
Record the quotient 8 as the next digit in the result. 
Result so far: 418.0
Deduct 168 from 176 and we're left with 8.
Include the next digit (2) from the dividend after 8, then repeat: 82 / 21

On to step 5:
If we divide 82 by 21, we get 3 and a remainder of 19.
Use 3 as the next digit of our solution. 
Result so far: 4183.0
Deduct 63 from 82 and we're left with 19.
Grab the next digit (9) from the dividend, add it to 19, then carry on: 199 / 21

Moving on to step 6:
21 goes into 199 9 times with a remainder of 10.
The next digit of our result is 9. 
Result so far: 41839.0
The remainder is 10 after subtracting 189 from 199.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 7:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 41839.4
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.

Step 8:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 41839.47
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.

Going ahead to step 9:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 41839.476
Deduct 126 from 130 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.

Let's proceed to step 10:
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: 41839.4761
If we subtract 21 from 40, 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.

Advancing to step 11:
190 divided by 21 is 9 with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 41839.47619
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.

Advancing to step 12:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 41839.47619
The remainder is 10 after subtracting 0 from 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 13:
21 goes into 100 4 times with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 41839.4761904
Subtract 84 from 100 to get 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 14:
When dividing 160 by 21, we get 7 with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 41839.47619047
Subtracting 147 from 160 leaves us 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.

After the division, we end up with 41839.47619047 and a remainder of 1.3e-08.