Let's divide 121305 by 21
Our goal is to divide 121305 by 21.

Going ahead to step 1:
The number 21 fits into 1 0 times, leaving a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Bring next digit (2) of the dividend behind the 1 and repeat the process: 12 / 21

Let's proceed to step 2:
12 divided by 21 is 0 with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 12 to get 12.
Include the next digit (1) from the dividend after 12, then repeat: 121 / 21

Advancing to step 3:
If we divide 121 by 21, we get 5 and a remainder of 16.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
If we subtract 105 from 121, we get 16.
Append the next digit (3) from the dividend to 16 and continue with: 163 / 21

Step 4:
163 divided by 21 is 7 with a remainder of 16.
Put 7 as the next digit of the answer. 
Result so far: 57.0
Deduct 147 from 163 and we're left with 16.
Fetch the next digit (0) from the dividend, attach it to 16 and continue: 160 / 21

Let's proceed to step 5:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 577.0
If we subtract 147 from 160, we get 13.
Take the next digit (5) from the dividend and append it to 13, then repeat: 135 / 21

Let's proceed to step 6:
135 divided by 21 is 6 with a remainder of 9.
Record the quotient 6 as the next digit in the result. 
Result so far: 5776.0
Subtracting 126 from 135 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.
Record the quotient 4 as the next digit in the result. 
Result so far: 5776.4
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.

On to step 8:
60 divided by 21 is 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 5776.42
Subtracting 42 from 60 leaves us 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:
When dividing 180 by 21, we get 8 with a remainder of 12.
The number 8 becomes the next digit in our result. 
Result so far: 5776.428
Subtract 168 from 180 to get 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:
120 divided by 21 is 5 with a remainder of 15.
Write down 5 as next digit of the result. 
Result so far: 5776.4285
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.

Advancing to step 11:
21 goes into 150 7 times with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 5776.42857
Subtracting 147 from 150 leaves us 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.

On to step 12:
When dividing 30 by 21, we get 1 with a remainder of 9.
Write down 1 as next digit of the result. 
Result so far: 5776.428571
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.

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: 5776.4285714
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.

Going ahead to step 14:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The next digit of our result is 2. 
Result so far: 5776.42857142
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 5776.42857142 and a remainder of 1.8e-08.