Let's divide 21591851 by 505
We're looking to find how many times 505 goes into 21591851.

Advancing to step 1:
2 divided by 505 is 0 with 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 (1) from the dividend and append it to 2, then repeat: 21 / 505

On to step 2:
If we divide 21 by 505, we get 0 and a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Bring next digit (5) of the dividend behind the 21 and repeat the process: 215 / 505

Step 3:
When dividing 215 by 505, we get 0 with a remainder of 215.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 215, we get 215.
Include the next digit (9) from the dividend after 215, then repeat: 2159 / 505

Step 4:
2159 divided by 505 is 4 with a remainder of 139.
The next digit of our result is 4. 
Result so far: 4.0
Deduct 2020 from 2159 and we're left with 139.
Bring next digit (1) of the dividend behind the 139 and repeat the process: 1391 / 505

Going ahead to step 5:
505 goes into 1391 2 times with a remainder of 381.
The next digit of our result is 2. 
Result so far: 42.0
Deduct 1010 from 1391 and we're left with 381.
Take the next digit (8) from the dividend and append it to 381, then repeat: 3818 / 505

Moving on to step 6:
When dividing 3818 by 505, we get 7 with a remainder of 283.
The number 7 becomes the next digit in our result. 
Result so far: 427.0
The remainder is 283 after subtracting 3535 from 3818.
Append the next digit (5) from the dividend to 283 and continue with: 2835 / 505

On to step 7:
2835 divided by 505 is 5 with a remainder of 310.
The next digit of our result is 5. 
Result so far: 4275.0
If we take 2525 away from 2835, we end up with 310.
Grab the next digit (1) from the dividend, add it to 310, then carry on: 3101 / 505

Going ahead to step 8:
505 can be fit into 3101 6 times, resulting in a remainder of 71.
The number 6 becomes the next digit in our result. 
Result so far: 42756.0
If we take 3030 away from 3101, we end up with 71.
Since there are no more digits in the dividend, we add a zero to the remainder making it 710, and continue the process.

Going ahead to step 9:
When dividing 710 by 505, we get 1 with a remainder of 205.
Put 1 as the next digit of the answer. 
Result so far: 42756.1
Deduct 505 from 710 and we're left with 205.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2050, and continue the process.

On to step 10:
If we divide 2050 by 505, we get 4 and a remainder of 30.
Record the quotient 4 as the next digit in the result. 
Result so far: 42756.14
The remainder is 30 after subtracting 2020 from 2050.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 11:
505 goes into 300 0 times with a remainder of 300.
Record the quotient 0 as the next digit in the result. 
Result so far: 42756.14
If we take 0 away from 300, we end up with 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

Step 12:
When dividing 3000 by 505, we get 5 with a remainder of 475.
Put 5 as the next digit of the answer. 
Result so far: 42756.1405
If we take 2525 away from 3000, we end up with 475.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4750, and continue the process.

Advancing to step 13:
If we divide 4750 by 505, we get 9 and a remainder of 205.
Write down 9 as next digit of the result. 
Result so far: 42756.14059
Deduct 4545 from 4750 and we're left with 205.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2050, and continue the process.

Going ahead to step 14:
If we divide 2050 by 505, we get 4 and a remainder of 30.
The number 4 becomes the next digit in our result. 
Result so far: 42756.140594
Deduct 2020 from 2050 and we're left with 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Step 15:
If we divide 300 by 505, we get 0 and a remainder of 300.
Write down 0 as next digit of the result. 
Result so far: 42756.140594
Deduct 0 from 300 and we're left with 300.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3000, and continue the process.

Moving on to step 16:
If we divide 3000 by 505, we get 5 and a remainder of 475.
Write down 5 as next digit of the result. 
Result so far: 42756.14059405
If we subtract 2525 from 3000, we get 475.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4750, and continue the process.

The final outcome is 42756.14059405, with a leftover of 4.75e-07.