42001955 divided by 643 
We're looking to find how many times 643 goes into 42001955.

Moving on to step 1:
If we divide 4 by 643, we get 0 and a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Grab the next digit (2) from the dividend, add it to 4, then carry on: 42 / 643

On to step 2:
643 goes into 42 0 times with a remainder of 42.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 42 to get 42.
Grab the next digit (0) from the dividend, add it to 42, then carry on: 420 / 643

Let's proceed to step 3:
If we divide 420 by 643, we get 0 and a remainder of 420.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 420 leaves us with 420.
Grab the next digit (0) from the dividend, add it to 420, then carry on: 4200 / 643

Moving on to step 4:
643 goes into 4200 6 times with a remainder of 342.
Use 6 as the next digit of our solution. 
Result so far: 6.0
If we subtract 3858 from 4200, we get 342.
Take the next digit (1) from the dividend and append it to 342, then repeat: 3421 / 643

Going ahead to step 5:
3421 divided by 643 is 5 with a remainder of 206.
Use 5 as the next digit of our solution. 
Result so far: 65.0
If we subtract 3215 from 3421, we get 206.
Append the next digit (9) from the dividend to 206 and continue with: 2069 / 643

Step 6:
643 can be fit into 2069 3 times, resulting in a remainder of 140.
Put 3 as the next digit of the answer. 
Result so far: 653.0
Deduct 1929 from 2069 and we're left with 140.
Fetch the next digit (5) from the dividend, attach it to 140 and continue: 1405 / 643

Going ahead to step 7:
643 goes into 1405 2 times with a remainder of 119.
The number 2 becomes the next digit in our result. 
Result so far: 6532.0
If we take 1286 away from 1405, we end up with 119.
Grab the next digit (5) from the dividend, add it to 119, then carry on: 1195 / 643

Step 8:
The number 643 fits into 1195 1 times, leaving a remainder of 552.
Record the quotient 1 as the next digit in the result. 
Result so far: 65321.0
Deduct 643 from 1195 and we're left with 552.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5520, and continue the process.

Going ahead to step 9:
643 can be fit into 5520 8 times, resulting in a remainder of 376.
Use 8 as the next digit of our solution. 
Result so far: 65321.8
Subtracting 5144 from 5520 leaves us with 376.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3760, and continue the process.

Step 10:
When dividing 3760 by 643, we get 5 with a remainder of 545.
Use 5 as the next digit of our solution. 
Result so far: 65321.85
Deduct 3215 from 3760 and we're left with 545.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5450, and continue the process.

Going ahead to step 11:
643 can be fit into 5450 8 times, resulting in a remainder of 306.
Put 8 as the next digit of the answer. 
Result so far: 65321.858
If we take 5144 away from 5450, we end up with 306.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3060, and continue the process.

Step 12:
The number 643 fits into 3060 4 times, leaving a remainder of 488.
Record the quotient 4 as the next digit in the result. 
Result so far: 65321.8584
The remainder is 488 after subtracting 2572 from 3060.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4880, and continue the process.

Step 13:
When dividing 4880 by 643, we get 7 with a remainder of 379.
Use 7 as the next digit of our solution. 
Result so far: 65321.85847
If we take 4501 away from 4880, we end up with 379.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3790, and continue the process.

Going ahead to step 14:
The number 643 fits into 3790 5 times, leaving a remainder of 575.
The number 5 becomes the next digit in our result. 
Result so far: 65321.858475
Subtract 3215 from 3790 to get 575.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5750, and continue the process.

Step 15:
The number 643 fits into 5750 8 times, leaving a remainder of 606.
Put 8 as the next digit of the answer. 
Result so far: 65321.8584758
If we take 5144 away from 5750, we end up with 606.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6060, and continue the process.

On to step 16:
643 can be fit into 6060 9 times, resulting in a remainder of 273.
The number 9 becomes the next digit in our result. 
Result so far: 65321.85847589
Subtracting 5787 from 6060 leaves us with 273.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2730, and continue the process.

The final result is 65321.85847589 with a remainder of 2.73e-07.