We're dividing 90217500 by 21 
We want to divide 90217500 by 21.

Going ahead to step 1:
9 divided by 21 is 0 with a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 9 after subtracting 0 from 9.
Fetch the next digit (0) from the dividend, attach it to 9 and continue: 90 / 21

Advancing to step 2:
When dividing 90 by 21, we get 4 with a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 4.0
If we subtract 84 from 90, we get 6.
Include the next digit (2) from the dividend after 6, then repeat: 62 / 21

Advancing to step 3:
21 can be fit into 62 2 times, resulting in a remainder of 20.
Use 2 as the next digit of our solution. 
Result so far: 42.0
If we subtract 42 from 62, we get 20.
Append the next digit (1) from the dividend to 20 and continue with: 201 / 21

Going ahead to step 4:
If we divide 201 by 21, we get 9 and a remainder of 12.
Put 9 as the next digit of the answer. 
Result so far: 429.0
The remainder is 12 after subtracting 189 from 201.
Take the next digit (7) from the dividend and append it to 12, then repeat: 127 / 21

On to step 5:
If we divide 127 by 21, we get 6 and a remainder of 1.
Write down 6 as next digit of the result. 
Result so far: 4296.0
Subtract 126 from 127 to get 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 21

Moving on to step 6:
The number 21 fits into 15 0 times, leaving a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 42960.0
The remainder is 15 after subtracting 0 from 15.
Include the next digit (0) from the dividend after 15, then repeat: 150 / 21

Going ahead to step 7:
21 goes into 150 7 times with a remainder of 3.
The next digit of our result is 7. 
Result so far: 429607.0
Deduct 147 from 150 and we're left with 3.
Grab the next digit (0) from the dividend, add it to 3, then carry on: 30 / 21

Going ahead to step 8:
30 divided by 21 is 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 4296071.0
If we subtract 21 from 30, we 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.

Let's proceed to step 9:
The number 21 fits into 90 4 times, leaving a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 4296071.4
Subtract 84 from 90 to get 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 10:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 4296071.42
Deduct 42 from 60 and we're left 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.

Advancing to step 11:
If we divide 180 by 21, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 4296071.428
Deduct 168 from 180 and we're left 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 12:
120 divided by 21 is 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 4296071.4285
Deduct 105 from 120 and we're left 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.

On to step 13:
21 goes into 150 7 times with a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 4296071.42857
If we subtract 147 from 150, we get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 14:
If we divide 30 by 21, we get 1 and a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 4296071.428571
Subtracting 21 from 30 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.

Advancing to step 15:
21 goes into 90 4 times with a remainder of 6.
The next digit of our result is 4. 
Result so far: 4296071.4285714
The remainder is 6 after subtracting 84 from 90.
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 16:
The number 21 fits into 60 2 times, leaving a remainder of 18.
Put 2 as the next digit of the answer. 
Result so far: 4296071.42857142
If we subtract 42 from 60, we get 18.
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 4296071.42857142 and a remainder of 1.8e-08.