Let's divide 251947 by 21
We want to divide 251947 by 21.

Going ahead to step 1:
The number 21 fits into 2 0 times, leaving a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Take the next digit (5) from the dividend and append it to 2, then repeat: 25 / 21

On to step 2:
When dividing 25 by 21, we get 1 with a remainder of 4.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 21 from 25 and we're left with 4.
Append the next digit (1) from the dividend to 4 and continue with: 41 / 21

Going ahead to step 3:
41 divided by 21 is 1 with a remainder of 20.
Write down 1 as next digit of the result. 
Result so far: 11.0
Subtracting 21 from 41 leaves us with 20.
Append the next digit (9) from the dividend to 20 and continue with: 209 / 21

On to step 4:
21 goes into 209 9 times with a remainder of 20.
Record the quotient 9 as the next digit in the result. 
Result so far: 119.0
Deduct 189 from 209 and we're left with 20.
Bring next digit (4) of the dividend behind the 20 and repeat the process: 204 / 21

Advancing to step 5:
21 goes into 204 9 times with a remainder of 15.
Use 9 as the next digit of our solution. 
Result so far: 1199.0
If we subtract 189 from 204, we get 15.
Include the next digit (7) from the dividend after 15, then repeat: 157 / 21

Moving on to step 6:
If we divide 157 by 21, we get 7 and a remainder of 10.
The number 7 becomes the next digit in our result. 
Result so far: 11997.0
If we take 147 away from 157, we end up 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.

Going ahead to step 7:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 11997.4
If we subtract 84 from 100, we 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.

Moving on to step 8:
21 can be fit into 160 7 times, resulting in a remainder of 13.
The next digit of our result is 7. 
Result so far: 11997.47
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.

On to step 9:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 11997.476
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.

Step 10:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 11997.4761
Subtract 21 from 40 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.

Advancing to step 11:
190 divided by 21 is 9 with a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 11997.47619
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.

Moving on to step 12:
If we divide 10 by 21, we get 0 and a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 11997.47619
The remainder is 10 after subtracting 0 from 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 13:
21 can be fit into 100 4 times, resulting in a remainder of 16.
Write down 4 as next digit of the result. 
Result so far: 11997.4761904
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.

Step 14:
21 goes into 160 7 times with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 11997.47619047
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.

After the division, we end up with 11997.47619047 and a remainder of 1.3e-08.