91705890 ÷ 21 
Let's see how many times 21 fits into 91705890.

Moving on to step 1:
21 can be fit into 9 0 times, resulting in a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 9, we get 9.
Bring next digit (1) of the dividend behind the 9 and repeat the process: 91 / 21

Advancing to step 2:
21 can be fit into 91 4 times, resulting in a remainder of 7.
Write down 4 as next digit of the result. 
Result so far: 4.0
If we take 84 away from 91, we end up with 7.
Bring next digit (7) of the dividend behind the 7 and repeat the process: 77 / 21

Moving on to step 3:
When dividing 77 by 21, we get 3 with a remainder of 14.
Use 3 as the next digit of our solution. 
Result so far: 43.0
Subtracting 63 from 77 leaves us with 14.
Include the next digit (0) from the dividend after 14, then repeat: 140 / 21

Going ahead to step 4:
21 goes into 140 6 times with a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 436.0
If we take 126 away from 140, we end up with 14.
Grab the next digit (5) from the dividend, add it to 14, then carry on: 145 / 21

Going ahead to step 5:
If we divide 145 by 21, we get 6 and a remainder of 19.
Put 6 as the next digit of the answer. 
Result so far: 4366.0
Subtract 126 from 145 to get 19.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 21

Let's proceed to step 6:
The number 21 fits into 198 9 times, leaving a remainder of 9.
The number 9 becomes the next digit in our result. 
Result so far: 43669.0
If we take 189 away from 198, we end up with 9.
Grab the next digit (9) from the dividend, add it to 9, then carry on: 99 / 21

Let's proceed to step 7:
If we divide 99 by 21, we get 4 and a remainder of 15.
Write down 4 as next digit of the result. 
Result so far: 436694.0
The remainder is 15 after subtracting 84 from 99.
Append the next digit (0) from the dividend to 15 and continue with: 150 / 21

Let's proceed to step 8:
If we divide 150 by 21, we get 7 and a remainder of 3.
The next digit of our result is 7. 
Result so far: 4366947.0
Subtract 147 from 150 to 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.

Advancing to step 9:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 4366947.1
If we take 21 away from 30, we end up 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.

Let's proceed to step 10:
21 can be fit into 90 4 times, resulting in a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 4366947.14
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.

Moving on to step 11:
60 divided by 21 is 2 with a remainder of 18.
Use 2 as the next digit of our solution. 
Result so far: 4366947.142
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.

Going ahead to step 12:
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: 4366947.1428
The remainder is 12 after subtracting 168 from 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Going ahead to step 13:
When dividing 120 by 21, we get 5 with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 4366947.14285
If we take 105 away from 120, we end up 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.

Going ahead to step 14:
If we divide 150 by 21, we get 7 and a remainder of 3.
The next digit of our result is 7. 
Result so far: 4366947.142857
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.

Step 15:
If we divide 30 by 21, we get 1 and a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 4366947.1428571
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.

Let's proceed to step 16:
When dividing 90 by 21, we get 4 with a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 4366947.14285714
Subtracting 84 from 90 leaves us 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.

Our division results in 4366947.14285714 with a remaining 6e-09.