We divide 19990102 by 643
We're looking to find how many times 643 goes into 19990102.

On to step 1:
643 goes into 1 0 times with a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Include the next digit (9) from the dividend after 1, then repeat: 19 / 643

On to step 2:
643 can be fit into 19 0 times, resulting in a remainder of 19.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 19 to get 19.
Grab the next digit (9) from the dividend, add it to 19, then carry on: 199 / 643

On to step 3:
643 goes into 199 0 times with a remainder of 199.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 199 after subtracting 0 from 199.
Grab the next digit (9) from the dividend, add it to 199, then carry on: 1999 / 643

Going ahead to step 4:
When dividing 1999 by 643, we get 3 with a remainder of 70.
The next digit of our result is 3. 
Result so far: 3.0
Subtract 1929 from 1999 to get 70.
Include the next digit (0) from the dividend after 70, then repeat: 700 / 643

On to step 5:
The number 643 fits into 700 1 times, leaving a remainder of 57.
Record the quotient 1 as the next digit in the result. 
Result so far: 31.0
Deduct 643 from 700 and we're left with 57.
Grab the next digit (1) from the dividend, add it to 57, then carry on: 571 / 643

On to step 6:
When dividing 571 by 643, we get 0 with a remainder of 571.
Record the quotient 0 as the next digit in the result. 
Result so far: 310.0
Deduct 0 from 571 and we're left with 571.
Grab the next digit (0) from the dividend, add it to 571, then carry on: 5710 / 643

Moving on to step 7:
643 can be fit into 5710 8 times, resulting in a remainder of 566.
Record the quotient 8 as the next digit in the result. 
Result so far: 3108.0
If we take 5144 away from 5710, we end up with 566.
Include the next digit (2) from the dividend after 566, then repeat: 5662 / 643

Going ahead to step 8:
The number 643 fits into 5662 8 times, leaving a remainder of 518.
Put 8 as the next digit of the answer. 
Result so far: 31088.0
If we take 5144 away from 5662, we end up with 518.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5180, and continue the process.

Advancing to step 9:
643 goes into 5180 8 times with a remainder of 36.
Write down 8 as next digit of the result. 
Result so far: 31088.8
The remainder is 36 after subtracting 5144 from 5180.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Moving on to step 10:
If we divide 360 by 643, we get 0 and a remainder of 360.
Use 0 as the next digit of our solution. 
Result so far: 31088.8
If we subtract 0 from 360, we get 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Moving on to step 11:
When dividing 3600 by 643, we get 5 with a remainder of 385.
Use 5 as the next digit of our solution. 
Result so far: 31088.805
Deduct 3215 from 3600 and we're left with 385.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3850, and continue the process.

Going ahead to step 12:
643 goes into 3850 5 times with a remainder of 635.
Use 5 as the next digit of our solution. 
Result so far: 31088.8055
If we take 3215 away from 3850, we end up with 635.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6350, and continue the process.

The quotient of the division is 31088.8055, and the remainder is 0.00635.