Let's divide 751399 by 21
We want to divide 751399 by 21.

Advancing to step 1:
21 can be fit into 7 0 times, resulting in a remainder of 7.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 7 leaves us with 7.
Include the next digit (5) from the dividend after 7, then repeat: 75 / 21

Step 2:
21 can be fit into 75 3 times, resulting in a remainder of 12.
Write down 3 as next digit of the result. 
Result so far: 3.0
Subtract 63 from 75 to get 12.
Include the next digit (1) from the dividend after 12, then repeat: 121 / 21

On to step 3:
If we divide 121 by 21, we get 5 and a remainder of 16.
Put 5 as the next digit of the answer. 
Result so far: 35.0
Deduct 105 from 121 and we're left with 16.
Append the next digit (3) from the dividend to 16 and continue with: 163 / 21

On to step 4:
21 can be fit into 163 7 times, resulting in a remainder of 16.
The number 7 becomes the next digit in our result. 
Result so far: 357.0
If we subtract 147 from 163, we get 16.
Grab the next digit (9) from the dividend, add it to 16, then carry on: 169 / 21

Moving on to step 5:
If we divide 169 by 21, we get 8 and a remainder of 1.
Record the quotient 8 as the next digit in the result. 
Result so far: 3578.0
Subtract 168 from 169 to get 1.
Grab the next digit (9) from the dividend, add it to 1, then carry on: 19 / 21

Moving on to step 6:
21 goes into 19 0 times with a remainder of 19.
The number 0 becomes the next digit in our result. 
Result so far: 35780.0
Subtract 0 from 19 to 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.

On to step 7:
21 goes into 190 9 times with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 35780.9
Deduct 189 from 190 and we're left 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.

Going ahead to step 8:
If we divide 10 by 21, we get 0 and a remainder of 10.
The next digit of our result is 0. 
Result so far: 35780.9
Subtract 0 from 10 to get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 9:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 35780.904
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

On to step 10:
21 can be fit into 160 7 times, resulting in a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 35780.9047
If we take 147 away from 160, we end up 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.

Moving on to step 11:
When dividing 130 by 21, we get 6 with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 35780.90476
Subtracting 126 from 130 leaves us 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.

Advancing to step 12:
The number 21 fits into 40 1 times, leaving a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 35780.904761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 13:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 35780.9047619
Deduct 189 from 190 and we're left 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.

Step 14:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 35780.9047619
Subtracting 0 from 10 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The final result is 35780.9047619 with a remainder of 1e-08.