643239 ÷ 91 
We want to figure out the number of times 643239 can be divided by 91.

Moving on to step 1:
6 divided by 91 is 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 6, we end up with 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 91

Advancing to step 2:
91 can be fit into 64 0 times, resulting in a remainder of 64.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 64 after subtracting 0 from 64.
Append the next digit (3) from the dividend to 64 and continue with: 643 / 91

Moving on to step 3:
91 goes into 643 7 times with a remainder of 6.
The number 7 becomes the next digit in our result. 
Result so far: 7.0
Deduct 637 from 643 and we're left with 6.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 91

Step 4:
If we divide 62 by 91, we get 0 and a remainder of 62.
The next digit of our result is 0. 
Result so far: 70.0
If we subtract 0 from 62, we get 62.
Grab the next digit (3) from the dividend, add it to 62, then carry on: 623 / 91

Let's proceed to step 5:
If we divide 623 by 91, we get 6 and a remainder of 77.
Write down 6 as next digit of the result. 
Result so far: 706.0
The remainder is 77 after subtracting 546 from 623.
Grab the next digit (9) from the dividend, add it to 77, then carry on: 779 / 91

Advancing to step 6:
When dividing 779 by 91, we get 8 with a remainder of 51.
The number 8 becomes the next digit in our result. 
Result so far: 7068.0
If we subtract 728 from 779, we get 51.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

Moving on to step 7:
When dividing 510 by 91, we get 5 with a remainder of 55.
Record the quotient 5 as the next digit in the result. 
Result so far: 7068.5
If we subtract 455 from 510, we get 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Let's proceed to step 8:
When dividing 550 by 91, we get 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 7068.56
The remainder is 4 after subtracting 546 from 550.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Going ahead to step 9:
If we divide 40 by 91, we get 0 and a remainder of 40.
Put 0 as the next digit of the answer. 
Result so far: 7068.56
If we subtract 0 from 40, we get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 10:
When dividing 400 by 91, we get 4 with a remainder of 36.
Write down 4 as next digit of the result. 
Result so far: 7068.5604
Deduct 364 from 400 and we're left with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

On to step 11:
91 can be fit into 360 3 times, resulting in a remainder of 87.
Put 3 as the next digit of the answer. 
Result so far: 7068.56043
The remainder is 87 after subtracting 273 from 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 870, and continue the process.

Moving on to step 12:
When dividing 870 by 91, we get 9 with a remainder of 51.
The next digit of our result is 9. 
Result so far: 7068.560439
The remainder is 51 after subtracting 819 from 870.
Since there are no more digits in the dividend, we add a zero to the remainder making it 510, and continue the process.

On to step 13:
91 goes into 510 5 times with a remainder of 55.
The next digit of our result is 5. 
Result so far: 7068.5604395
If we take 455 away from 510, we end up with 55.
Since there are no more digits in the dividend, we add a zero to the remainder making it 550, and continue the process.

Advancing to step 14:
91 can be fit into 550 6 times, resulting in a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 7068.56043956
The remainder is 4 after subtracting 546 from 550.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The quotient of the division is 7068.56043956, and the remainder is 4e-09.