We look at the division of 991229 by 21 
We want to figure out the number of times 991229 can be divided by 21.

On to step 1:
21 goes into 9 0 times with a remainder of 9.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 21

On to step 2:
21 can be fit into 99 4 times, resulting in a remainder of 15.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we subtract 84 from 99, we get 15.
Append the next digit (1) from the dividend to 15 and continue with: 151 / 21

Moving on to step 3:
When dividing 151 by 21, we get 7 with a remainder of 4.
The number 7 becomes the next digit in our result. 
Result so far: 47.0
If we take 147 away from 151, we end up with 4.
Include the next digit (2) from the dividend after 4, then repeat: 42 / 21

Advancing to step 4:
If we divide 42 by 21, we get 2 and a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 472.0
Subtracting 42 from 42 leaves us with 0.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 21

Going ahead to step 5:
21 can be fit into 2 0 times, resulting in a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 4720.0
Subtracting 0 from 2 leaves us with 2.
Append the next digit (9) from the dividend to 2 and continue with: 29 / 21

Step 6:
When dividing 29 by 21, we get 1 with a remainder of 8.
Record the quotient 1 as the next digit in the result. 
Result so far: 47201.0
Subtracting 21 from 29 leaves us with 8.
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 7:
80 divided by 21 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 47201.3
If we subtract 63 from 80, we get 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:
The number 21 fits into 170 8 times, leaving a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 47201.38
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:
21 goes into 20 0 times with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 47201.38
If we take 0 away from 20, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 10:
When dividing 200 by 21, we get 9 with a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 47201.3809
Deduct 189 from 200 and we're left 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:
110 divided by 21 is 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 47201.38095
Subtracting 105 from 110 leaves us 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.

Moving on to step 12:
If we divide 50 by 21, we get 2 and a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 47201.380952
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 13:
If we divide 80 by 21, we get 3 and a remainder of 17.
Write down 3 as next digit of the result. 
Result so far: 47201.3809523
Deduct 63 from 80 and we're left 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.

Moving on to step 14:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 47201.38095238
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.

In conclusion, the division gives 47201.38095238 with a balance of 2e-09.