We look at the division of 6683840 by 643 
We want to divide 6683840 by 643.

Step 1:
643 can be fit into 6 0 times, resulting in 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.
Include the next digit (6) from the dividend after 6, then repeat: 66 / 643

Step 2:
The number 643 fits into 66 0 times, leaving a remainder of 66.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 66 leaves us with 66.
Take the next digit (8) from the dividend and append it to 66, then repeat: 668 / 643

Step 3:
The number 643 fits into 668 1 times, leaving a remainder of 25.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtract 643 from 668 to get 25.
Fetch the next digit (3) from the dividend, attach it to 25 and continue: 253 / 643

Step 4:
If we divide 253 by 643, we get 0 and a remainder of 253.
Write down 0 as next digit of the result. 
Result so far: 10.0
If we take 0 away from 253, we end up with 253.
Grab the next digit (8) from the dividend, add it to 253, then carry on: 2538 / 643

Moving on to step 5:
If we divide 2538 by 643, we get 3 and a remainder of 609.
Put 3 as the next digit of the answer. 
Result so far: 103.0
If we subtract 1929 from 2538, we get 609.
Bring next digit (4) of the dividend behind the 609 and repeat the process: 6094 / 643

Going ahead to step 6:
643 can be fit into 6094 9 times, resulting in a remainder of 307.
Record the quotient 9 as the next digit in the result. 
Result so far: 1039.0
Deduct 5787 from 6094 and we're left with 307.
Fetch the next digit (0) from the dividend, attach it to 307 and continue: 3070 / 643

Going ahead to step 7:
643 goes into 3070 4 times with a remainder of 498.
The number 4 becomes the next digit in our result. 
Result so far: 10394.0
If we subtract 2572 from 3070, we get 498.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4980, and continue the process.

Advancing to step 8:
When dividing 4980 by 643, we get 7 with a remainder of 479.
Use 7 as the next digit of our solution. 
Result so far: 10394.7
If we subtract 4501 from 4980, we get 479.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4790, and continue the process.

Advancing to step 9:
4790 divided by 643 is 7 with a remainder of 289.
Write down 7 as next digit of the result. 
Result so far: 10394.77
Deduct 4501 from 4790 and we're left with 289.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2890, and continue the process.

The final result is 10394.77 with a remainder of 0.289.