643942 ÷ 28 
We want to divide 643942 by 28.

Going ahead to step 1:
If we divide 6 by 28, we get 0 and a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 28

Step 2:
If we divide 64 by 28, we get 2 and a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 2.0
Subtracting 56 from 64 leaves us with 8.
Append the next digit (3) from the dividend to 8 and continue with: 83 / 28

On to step 3:
83 divided by 28 is 2 with a remainder of 27.
Record the quotient 2 as the next digit in the result. 
Result so far: 22.0
Subtract 56 from 83 to get 27.
Include the next digit (9) from the dividend after 27, then repeat: 279 / 28

Let's proceed to step 4:
When dividing 279 by 28, we get 9 with a remainder of 27.
Put 9 as the next digit of the answer. 
Result so far: 229.0
If we subtract 252 from 279, we get 27.
Append the next digit (4) from the dividend to 27 and continue with: 274 / 28

Moving on to step 5:
If we divide 274 by 28, we get 9 and a remainder of 22.
Use 9 as the next digit of our solution. 
Result so far: 2299.0
Subtract 252 from 274 to get 22.
Fetch the next digit (2) from the dividend, attach it to 22 and continue: 222 / 28

Going ahead to step 6:
28 goes into 222 7 times with a remainder of 26.
Record the quotient 7 as the next digit in the result. 
Result so far: 22997.0
Deduct 196 from 222 and we're left with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

On to step 7:
If we divide 260 by 28, we get 9 and a remainder of 8.
The next digit of our result is 9. 
Result so far: 22997.9
If we subtract 252 from 260, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 8:
80 divided by 28 is 2 with a remainder of 24.
Put 2 as the next digit of the answer. 
Result so far: 22997.92
The remainder is 24 after subtracting 56 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 9:
When dividing 240 by 28, we get 8 with a remainder of 16.
Put 8 as the next digit of the answer. 
Result so far: 22997.928
If we take 224 away from 240, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 10:
28 goes into 160 5 times with a remainder of 20.
The number 5 becomes the next digit in our result. 
Result so far: 22997.9285
If we take 140 away from 160, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Step 11:
If we divide 200 by 28, we get 7 and a remainder of 4.
The next digit of our result is 7. 
Result so far: 22997.92857
Subtract 196 from 200 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 12:
When dividing 40 by 28, we get 1 with a remainder of 12.
Put 1 as the next digit of the answer. 
Result so far: 22997.928571
Deduct 28 from 40 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 13:
When dividing 120 by 28, we get 4 with a remainder of 8.
The number 4 becomes the next digit in our result. 
Result so far: 22997.9285714
Subtracting 112 from 120 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 14:
If we divide 80 by 28, we get 2 and a remainder of 24.
Put 2 as the next digit of the answer. 
Result so far: 22997.92857142
Subtracting 56 from 80 leaves us with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

The final outcome is 22997.92857142, with a leftover of 2.4e-08.