Let's divide 257336 by 21
We want to figure out the number of times 257336 can be divided by 21.

On to step 1:
21 goes into 2 0 times with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Fetch the next digit (5) from the dividend, attach it to 2 and continue: 25 / 21

Step 2:
25 divided by 21 is 1 with a remainder of 4.
The next digit of our result is 1. 
Result so far: 1.0
Subtracting 21 from 25 leaves us with 4.
Grab the next digit (7) from the dividend, add it to 4, then carry on: 47 / 21

Moving on to step 3:
When dividing 47 by 21, we get 2 with a remainder of 5.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
If we subtract 42 from 47, we get 5.
Include the next digit (3) from the dividend after 5, then repeat: 53 / 21

Moving on to step 4:
The number 21 fits into 53 2 times, leaving a remainder of 11.
Record the quotient 2 as the next digit in the result. 
Result so far: 122.0
The remainder is 11 after subtracting 42 from 53.
Include the next digit (3) from the dividend after 11, then repeat: 113 / 21

Advancing to step 5:
The number 21 fits into 113 5 times, leaving a remainder of 8.
Put 5 as the next digit of the answer. 
Result so far: 1225.0
If we take 105 away from 113, we end up with 8.
Fetch the next digit (6) from the dividend, attach it to 8 and continue: 86 / 21

Moving on to step 6:
The number 21 fits into 86 4 times, leaving a remainder of 2.
Record the quotient 4 as the next digit in the result. 
Result so far: 12254.0
Deduct 84 from 86 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 7:
If we divide 20 by 21, we get 0 and a remainder of 20.
Record the quotient 0 as the next digit in the result. 
Result so far: 12254.0
Subtract 0 from 20 to get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 8:
The number 21 fits into 200 9 times, leaving a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 12254.09
Subtracting 189 from 200 leaves us with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 9:
21 goes into 110 5 times with a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 12254.095
Subtract 105 from 110 to get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 10:
If we divide 50 by 21, we get 2 and a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 12254.0952
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 11:
When dividing 80 by 21, we get 3 with a remainder of 17.
The next digit of our result is 3. 
Result so far: 12254.09523
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

On to step 12:
170 divided by 21 is 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 12254.095238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 13:
When dividing 20 by 21, we get 0 with a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 12254.095238
The remainder is 20 after subtracting 0 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 14:
21 goes into 200 9 times with a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 12254.09523809
If we take 189 away from 200, we end up with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

After the division, we end up with 12254.09523809 and a remainder of 1.1e-08.