Let's divide 171222 by 21
We're looking to find how many times 21 goes into 171222.

Moving on to step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Include the next digit (7) from the dividend after 1, then repeat: 17 / 21

Let's proceed to step 2:
21 can be fit into 17 0 times, resulting in a remainder of 17.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 17 after subtracting 0 from 17.
Grab the next digit (1) from the dividend, add it to 17, then carry on: 171 / 21

Let's proceed to step 3:
When dividing 171 by 21, we get 8 with a remainder of 3.
Put 8 as the next digit of the answer. 
Result so far: 8.0
Subtracting 168 from 171 leaves us with 3.
Grab the next digit (2) from the dividend, add it to 3, then carry on: 32 / 21

Moving on to step 4:
21 can be fit into 32 1 times, resulting in a remainder of 11.
Record the quotient 1 as the next digit in the result. 
Result so far: 81.0
If we take 21 away from 32, we end up with 11.
Include the next digit (2) from the dividend after 11, then repeat: 112 / 21

Moving on to step 5:
The number 21 fits into 112 5 times, leaving a remainder of 7.
Record the quotient 5 as the next digit in the result. 
Result so far: 815.0
Subtracting 105 from 112 leaves us with 7.
Bring next digit (2) of the dividend behind the 7 and repeat the process: 72 / 21

Let's proceed to step 6:
21 goes into 72 3 times with a remainder of 9.
Record the quotient 3 as the next digit in the result. 
Result so far: 8153.0
Subtracting 63 from 72 leaves us with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 7:
21 goes into 90 4 times with a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 8153.4
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Step 8:
21 can be fit into 60 2 times, resulting in a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 8153.42
If we take 42 away from 60, we end up with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

On to step 9:
If we divide 180 by 21, we get 8 and a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 8153.428
If we take 168 away from 180, we end up with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Moving on to step 10:
21 goes into 120 5 times with a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 8153.4285
Subtracting 105 from 120 leaves us with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 11:
21 can be fit into 150 7 times, resulting in a remainder of 3.
The number 7 becomes the next digit in our result. 
Result so far: 8153.42857
Deduct 147 from 150 and we're left with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 12:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 8153.428571
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 13:
If we divide 90 by 21, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 8153.4285714
Deduct 84 from 90 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 14:
When dividing 60 by 21, we get 2 with a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 8153.42857142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

After the division, we end up with 8153.42857142 and a remainder of 1.8e-08.