We look at the division of 755491 by 21 
We want to figure out the number of times 755491 can be divided by 21.

Advancing to step 1:
7 divided by 21 is 0 with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 7, we end up with 7.
Take the next digit (5) from the dividend and append it to 7, then repeat: 75 / 21

Step 2:
75 divided by 21 is 3 with a remainder of 12.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Deduct 63 from 75 and we're left with 12.
Bring next digit (5) of the dividend behind the 12 and repeat the process: 125 / 21

Going ahead to step 3:
The number 21 fits into 125 5 times, leaving a remainder of 20.
Put 5 as the next digit of the answer. 
Result so far: 35.0
Subtract 105 from 125 to get 20.
Append the next digit (4) from the dividend to 20 and continue with: 204 / 21

Step 4:
204 divided by 21 is 9 with a remainder of 15.
Put 9 as the next digit of the answer. 
Result so far: 359.0
The remainder is 15 after subtracting 189 from 204.
Bring next digit (9) of the dividend behind the 15 and repeat the process: 159 / 21

Moving on to step 5:
159 divided by 21 is 7 with a remainder of 12.
Write down 7 as next digit of the result. 
Result so far: 3597.0
Deduct 147 from 159 and we're left with 12.
Append the next digit (1) from the dividend to 12 and continue with: 121 / 21

On to step 6:
121 divided by 21 is 5 with a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 35975.0
Subtract 105 from 121 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 7:
If we divide 160 by 21, we get 7 and a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 35975.7
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

On to step 8:
If we divide 130 by 21, we get 6 and a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 35975.76
If we take 126 away from 130, we end up 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.

Step 9:
When dividing 40 by 21, we get 1 with a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 35975.761
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.

Step 10:
If we divide 190 by 21, we get 9 and a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 35975.7619
The remainder is 1 after subtracting 189 from 190.
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 11:
10 divided by 21 is 0 with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 35975.7619
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.

Advancing to step 12:
If we divide 100 by 21, we get 4 and a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 35975.761904
If we take 84 away from 100, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 13:
21 can be fit into 160 7 times, resulting in a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 35975.7619047
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Advancing to step 14:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 35975.76190476
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.

The final result is 35975.76190476 with a remainder of 4e-09.