76388401 divided by 643 
We want to figure out the number of times 76388401 can be divided by 643.

Advancing to step 1:
643 goes into 7 0 times with a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 7, we get 7.
Fetch the next digit (6) from the dividend, attach it to 7 and continue: 76 / 643

Moving on to step 2:
76 divided by 643 is 0 with a remainder of 76.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 76 leaves us with 76.
Fetch the next digit (3) from the dividend, attach it to 76 and continue: 763 / 643

Going ahead to step 3:
763 divided by 643 is 1 with a remainder of 120.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 643 from 763 leaves us with 120.
Take the next digit (8) from the dividend and append it to 120, then repeat: 1208 / 643

Moving on to step 4:
643 can be fit into 1208 1 times, resulting in a remainder of 565.
Write down 1 as next digit of the result. 
Result so far: 11.0
If we take 643 away from 1208, we end up with 565.
Bring next digit (8) of the dividend behind the 565 and repeat the process: 5658 / 643

Step 5:
643 goes into 5658 8 times with a remainder of 514.
The next digit of our result is 8. 
Result so far: 118.0
Deduct 5144 from 5658 and we're left with 514.
Append the next digit (4) from the dividend to 514 and continue with: 5144 / 643

On to step 6:
5144 divided by 643 is 8 with a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 1188.0
If we subtract 5144 from 5144, we get 0.
Include the next digit (0) from the dividend after 0, then repeat: 0 / 643

Advancing to step 7:
If we divide 0 by 643, we get 0 and a remainder of 0.
The next digit of our result is 0. 
Result so far: 11880.0
Subtract 0 from 0 to get 0.
Append the next digit (1) from the dividend to 0 and continue with: 1 / 643

Going ahead to step 8:
If we divide 1 by 643, we get 0 and a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 118800.0
If we take 0 away from 1, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Let's proceed to step 9:
10 divided by 643 is 0 with a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 118800.0
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 10:
100 divided by 643 is 0 with a remainder of 100.
Use 0 as the next digit of our solution. 
Result so far: 118800.0
The remainder is 100 after subtracting 0 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

The final outcome is 118800.0, with a leftover of 0.1.