13057872 ÷ 645 
We want to figure out the number of times 13057872 can be divided by 645.

Advancing to step 1:
When dividing 1 by 645, we get 0 with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Append the next digit (3) from the dividend to 1 and continue with: 13 / 645

On to step 2:
13 divided by 645 is 0 with a remainder of 13.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 13 to get 13.
Take the next digit (0) from the dividend and append it to 13, then repeat: 130 / 645

Going ahead to step 3:
130 divided by 645 is 0 with a remainder of 130.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 130, we end up with 130.
Take the next digit (5) from the dividend and append it to 130, then repeat: 1305 / 645

Advancing to step 4:
645 goes into 1305 2 times with a remainder of 15.
The next digit of our result is 2. 
Result so far: 2.0
If we subtract 1290 from 1305, we get 15.
Fetch the next digit (7) from the dividend, attach it to 15 and continue: 157 / 645

Let's proceed to step 5:
If we divide 157 by 645, we get 0 and a remainder of 157.
Put 0 as the next digit of the answer. 
Result so far: 20.0
Subtract 0 from 157 to get 157.
Take the next digit (8) from the dividend and append it to 157, then repeat: 1578 / 645

Going ahead to step 6:
If we divide 1578 by 645, we get 2 and a remainder of 288.
Put 2 as the next digit of the answer. 
Result so far: 202.0
Deduct 1290 from 1578 and we're left with 288.
Append the next digit (7) from the dividend to 288 and continue with: 2887 / 645

Moving on to step 7:
2887 divided by 645 is 4 with a remainder of 307.
Record the quotient 4 as the next digit in the result. 
Result so far: 2024.0
The remainder is 307 after subtracting 2580 from 2887.
Append the next digit (2) from the dividend to 307 and continue with: 3072 / 645

On to step 8:
If we divide 3072 by 645, we get 4 and a remainder of 492.
The number 4 becomes the next digit in our result. 
Result so far: 20244.0
Subtracting 2580 from 3072 leaves us with 492.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4920, and continue the process.

Let's proceed to step 9:
4920 divided by 645 is 7 with a remainder of 405.
Put 7 as the next digit of the answer. 
Result so far: 20244.7
If we subtract 4515 from 4920, we get 405.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4050, and continue the process.

Let's proceed to step 10:
If we divide 4050 by 645, we get 6 and a remainder of 180.
Write down 6 as next digit of the result. 
Result so far: 20244.76
Subtracting 3870 from 4050 leaves us with 180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1800, and continue the process.

Going ahead to step 11:
645 goes into 1800 2 times with a remainder of 510.
Write down 2 as next digit of the result. 
Result so far: 20244.762
If we subtract 1290 from 1800, we get 510.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5100, and continue the process.

Let's proceed to step 12:
If we divide 5100 by 645, we get 7 and a remainder of 585.
Record the quotient 7 as the next digit in the result. 
Result so far: 20244.7627
Subtracting 4515 from 5100 leaves us with 585.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5850, and continue the process.

Step 13:
When dividing 5850 by 645, we get 9 with a remainder of 45.
Write down 9 as next digit of the result. 
Result so far: 20244.76279
The remainder is 45 after subtracting 5805 from 5850.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Step 14:
The number 645 fits into 450 0 times, leaving a remainder of 450.
Put 0 as the next digit of the answer. 
Result so far: 20244.76279
Subtract 0 from 450 to get 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4500, and continue the process.

Moving on to step 15:
4500 divided by 645 is 6 with a remainder of 630.
Record the quotient 6 as the next digit in the result. 
Result so far: 20244.7627906
Subtract 3870 from 4500 to get 630.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6300, and continue the process.

Moving on to step 16:
645 can be fit into 6300 9 times, resulting in a remainder of 495.
The number 9 becomes the next digit in our result. 
Result so far: 20244.76279069
If we subtract 5805 from 6300, we get 495.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4950, and continue the process.

The final result is 20244.76279069 with a remainder of 4.95e-07.