We're dividing 21201090 by 257 
We're looking to find how many times 257 goes into 21201090.

On to step 1:
257 can be fit into 2 0 times, resulting in a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 257

Moving on to step 2:
21 divided by 257 is 0 with a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Take the next digit (2) from the dividend and append it to 21, then repeat: 212 / 257

Moving on to step 3:
The number 257 fits into 212 0 times, leaving a remainder of 212.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 212 after subtracting 0 from 212.
Fetch the next digit (0) from the dividend, attach it to 212 and continue: 2120 / 257

Going ahead to step 4:
257 goes into 2120 8 times with a remainder of 64.
Write down 8 as next digit of the result. 
Result so far: 8.0
Deduct 2056 from 2120 and we're left with 64.
Include the next digit (1) from the dividend after 64, then repeat: 641 / 257

Let's proceed to step 5:
257 goes into 641 2 times with a remainder of 127.
The next digit of our result is 2. 
Result so far: 82.0
Subtracting 514 from 641 leaves us with 127.
Append the next digit (0) from the dividend to 127 and continue with: 1270 / 257

Let's proceed to step 6:
The number 257 fits into 1270 4 times, leaving a remainder of 242.
Use 4 as the next digit of our solution. 
Result so far: 824.0
Subtracting 1028 from 1270 leaves us with 242.
Bring next digit (9) of the dividend behind the 242 and repeat the process: 2429 / 257

Let's proceed to step 7:
If we divide 2429 by 257, we get 9 and a remainder of 116.
The number 9 becomes the next digit in our result. 
Result so far: 8249.0
If we take 2313 away from 2429, we end up with 116.
Bring next digit (0) of the dividend behind the 116 and repeat the process: 1160 / 257

Advancing to step 8:
The number 257 fits into 1160 4 times, leaving a remainder of 132.
The number 4 becomes the next digit in our result. 
Result so far: 82494.0
Subtract 1028 from 1160 to get 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

Advancing to step 9:
257 goes into 1320 5 times with a remainder of 35.
The next digit of our result is 5. 
Result so far: 82494.5
Deduct 1285 from 1320 and we're left with 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Moving on to step 10:
If we divide 350 by 257, we get 1 and a remainder of 93.
Use 1 as the next digit of our solution. 
Result so far: 82494.51
If we subtract 257 from 350, we get 93.
Since there are no more digits in the dividend, we add a zero to the remainder making it 930, and continue the process.

Let's proceed to step 11:
If we divide 930 by 257, we get 3 and a remainder of 159.
Use 3 as the next digit of our solution. 
Result so far: 82494.513
Subtracting 771 from 930 leaves us with 159.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1590, and continue the process.

Going ahead to step 12:
257 goes into 1590 6 times with a remainder of 48.
Put 6 as the next digit of the answer. 
Result so far: 82494.5136
Subtract 1542 from 1590 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Advancing to step 13:
The number 257 fits into 480 1 times, leaving a remainder of 223.
The number 1 becomes the next digit in our result. 
Result so far: 82494.51361
Subtract 257 from 480 to get 223.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2230, and continue the process.

On to step 14:
The number 257 fits into 2230 8 times, leaving a remainder of 174.
Record the quotient 8 as the next digit in the result. 
Result so far: 82494.513618
Deduct 2056 from 2230 and we're left with 174.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1740, and continue the process.

Going ahead to step 15:
257 goes into 1740 6 times with a remainder of 198.
Write down 6 as next digit of the result. 
Result so far: 82494.5136186
The remainder is 198 after subtracting 1542 from 1740.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1980, and continue the process.

Step 16:
257 can be fit into 1980 7 times, resulting in a remainder of 181.
Use 7 as the next digit of our solution. 
Result so far: 82494.51361867
Subtracting 1799 from 1980 leaves us with 181.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1810, and continue the process.

The final outcome is 82494.51361867, with a leftover of 1.81e-07.