Let's divide 19891957 by 648
We want to figure out the number of times 19891957 can be divided by 648.

Going ahead to step 1:
1 divided by 648 is 0 with a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 648

On to step 2:
19 divided by 648 is 0 with a remainder of 19.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 19 after subtracting 0 from 19.
Bring next digit (8) of the dividend behind the 19 and repeat the process: 198 / 648

On to step 3:
When dividing 198 by 648, we get 0 with a remainder of 198.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 198, we end up with 198.
Bring next digit (9) of the dividend behind the 198 and repeat the process: 1989 / 648

Going ahead to step 4:
648 can be fit into 1989 3 times, resulting in a remainder of 45.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 1944 from 1989 leaves us with 45.
Include the next digit (1) from the dividend after 45, then repeat: 451 / 648

Moving on to step 5:
When dividing 451 by 648, we get 0 with a remainder of 451.
Record the quotient 0 as the next digit in the result. 
Result so far: 30.0
If we subtract 0 from 451, we get 451.
Grab the next digit (9) from the dividend, add it to 451, then carry on: 4519 / 648

Advancing to step 6:
648 can be fit into 4519 6 times, resulting in a remainder of 631.
Use 6 as the next digit of our solution. 
Result so far: 306.0
If we subtract 3888 from 4519, we get 631.
Append the next digit (5) from the dividend to 631 and continue with: 6315 / 648

Moving on to step 7:
648 goes into 6315 9 times with a remainder of 483.
Record the quotient 9 as the next digit in the result. 
Result so far: 3069.0
Deduct 5832 from 6315 and we're left with 483.
Include the next digit (7) from the dividend after 483, then repeat: 4837 / 648

Moving on to step 8:
4837 divided by 648 is 7 with a remainder of 301.
The next digit of our result is 7. 
Result so far: 30697.0
If we subtract 4536 from 4837, we get 301.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3010, and continue the process.

Let's proceed to step 9:
The number 648 fits into 3010 4 times, leaving a remainder of 418.
The next digit of our result is 4. 
Result so far: 30697.4
If we take 2592 away from 3010, we end up with 418.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4180, and continue the process.

Advancing to step 10:
The number 648 fits into 4180 6 times, leaving a remainder of 292.
The next digit of our result is 6. 
Result so far: 30697.46
Subtract 3888 from 4180 to get 292.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2920, and continue the process.

Moving on to step 11:
648 goes into 2920 4 times with a remainder of 328.
Put 4 as the next digit of the answer. 
Result so far: 30697.464
If we subtract 2592 from 2920, we get 328.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3280, and continue the process.

On to step 12:
When dividing 3280 by 648, we get 5 with a remainder of 40.
Record the quotient 5 as the next digit in the result. 
Result so far: 30697.4645
If we take 3240 away from 3280, we end up with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Going ahead to step 13:
648 goes into 400 0 times with a remainder of 400.
The next digit of our result is 0. 
Result so far: 30697.4645
The remainder is 400 after subtracting 0 from 400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

Let's proceed to step 14:
When dividing 4000 by 648, we get 6 with a remainder of 112.
The next digit of our result is 6. 
Result so far: 30697.464506
If we subtract 3888 from 4000, we get 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

Moving on to step 15:
The number 648 fits into 1120 1 times, leaving a remainder of 472.
The next digit of our result is 1. 
Result so far: 30697.4645061
If we take 648 away from 1120, we end up with 472.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4720, and continue the process.

Let's proceed to step 16:
The number 648 fits into 4720 7 times, leaving a remainder of 184.
Record the quotient 7 as the next digit in the result. 
Result so far: 30697.46450617
Deduct 4536 from 4720 and we're left with 184.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1840, and continue the process.

The final outcome is 30697.46450617, with a leftover of 1.84e-07.