We look at the division of 21305257 by 145 
We want to divide 21305257 by 145.

On to step 1:
When dividing 2 by 145, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 145

On to step 2:
21 divided by 145 is 0 with a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Grab the next digit (3) from the dividend, add it to 21, then carry on: 213 / 145

Let's proceed to step 3:
When dividing 213 by 145, we get 1 with a remainder of 68.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
If we subtract 145 from 213, we get 68.
Include the next digit (0) from the dividend after 68, then repeat: 680 / 145

Step 4:
The number 145 fits into 680 4 times, leaving a remainder of 100.
Record the quotient 4 as the next digit in the result. 
Result so far: 14.0
If we take 580 away from 680, we end up with 100.
Include the next digit (5) from the dividend after 100, then repeat: 1005 / 145

Let's proceed to step 5:
145 goes into 1005 6 times with a remainder of 135.
Put 6 as the next digit of the answer. 
Result so far: 146.0
The remainder is 135 after subtracting 870 from 1005.
Fetch the next digit (2) from the dividend, attach it to 135 and continue: 1352 / 145

Let's proceed to step 6:
The number 145 fits into 1352 9 times, leaving a remainder of 47.
Use 9 as the next digit of our solution. 
Result so far: 1469.0
If we subtract 1305 from 1352, we get 47.
Include the next digit (5) from the dividend after 47, then repeat: 475 / 145

Going ahead to step 7:
If we divide 475 by 145, we get 3 and a remainder of 40.
Use 3 as the next digit of our solution. 
Result so far: 14693.0
Deduct 435 from 475 and we're left with 40.
Grab the next digit (7) from the dividend, add it to 40, then carry on: 407 / 145

Going ahead to step 8:
If we divide 407 by 145, we get 2 and a remainder of 117.
Put 2 as the next digit of the answer. 
Result so far: 146932.0
If we subtract 290 from 407, we get 117.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1170, and continue the process.

Let's proceed to step 9:
When dividing 1170 by 145, we get 8 with a remainder of 10.
The next digit of our result is 8. 
Result so far: 146932.8
If we take 1160 away from 1170, 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.

On to step 10:
The number 145 fits into 100 0 times, leaving a remainder of 100.
Put 0 as the next digit of the answer. 
Result so far: 146932.8
If we take 0 away from 100, we end up with 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Going ahead to step 11:
145 goes into 1000 6 times with a remainder of 130.
The number 6 becomes the next digit in our result. 
Result so far: 146932.806
If we take 870 away from 1000, we end up with 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1300, and continue the process.

On to step 12:
145 can be fit into 1300 8 times, resulting in a remainder of 140.
Use 8 as the next digit of our solution. 
Result so far: 146932.8068
If we subtract 1160 from 1300, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

On to step 13:
If we divide 1400 by 145, we get 9 and a remainder of 95.
Put 9 as the next digit of the answer. 
Result so far: 146932.80689
If we take 1305 away from 1400, we end up with 95.
Since there are no more digits in the dividend, we add a zero to the remainder making it 950, and continue the process.

Let's proceed to step 14:
When dividing 950 by 145, we get 6 with a remainder of 80.
Record the quotient 6 as the next digit in the result. 
Result so far: 146932.806896
Deduct 870 from 950 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Moving on to step 15:
800 divided by 145 is 5 with a remainder of 75.
Write down 5 as next digit of the result. 
Result so far: 146932.8068965
If we subtract 725 from 800, we get 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Moving on to step 16:
145 goes into 750 5 times with a remainder of 25.
Record the quotient 5 as the next digit in the result. 
Result so far: 146932.80689655
Subtracting 725 from 750 leaves us with 25.
Since there are no more digits in the dividend, we add a zero to the remainder making it 250, and continue the process.

The final result is 146932.80689655 with a remainder of 2.5e-08.