Let's divide 86710939 by 640
We want to figure out the number of times 86710939 can be divided by 640.

On to step 1:
If we divide 8 by 640, we get 0 and a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (6) of the dividend behind the 8 and repeat the process: 86 / 640

On to step 2:
The number 640 fits into 86 0 times, leaving a remainder of 86.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 86 to get 86.
Fetch the next digit (7) from the dividend, attach it to 86 and continue: 867 / 640

Going ahead to step 3:
640 goes into 867 1 times with a remainder of 227.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Deduct 640 from 867 and we're left with 227.
Take the next digit (1) from the dividend and append it to 227, then repeat: 2271 / 640

On to step 4:
640 can be fit into 2271 3 times, resulting in a remainder of 351.
Use 3 as the next digit of our solution. 
Result so far: 13.0
The remainder is 351 after subtracting 1920 from 2271.
Include the next digit (0) from the dividend after 351, then repeat: 3510 / 640

Let's proceed to step 5:
640 goes into 3510 5 times with a remainder of 310.
The next digit of our result is 5. 
Result so far: 135.0
If we take 3200 away from 3510, we end up with 310.
Include the next digit (9) from the dividend after 310, then repeat: 3109 / 640

Let's proceed to step 6:
640 can be fit into 3109 4 times, resulting in a remainder of 549.
The next digit of our result is 4. 
Result so far: 1354.0
Deduct 2560 from 3109 and we're left with 549.
Fetch the next digit (3) from the dividend, attach it to 549 and continue: 5493 / 640

Moving on to step 7:
If we divide 5493 by 640, we get 8 and a remainder of 373.
Put 8 as the next digit of the answer. 
Result so far: 13548.0
If we subtract 5120 from 5493, we get 373.
Bring next digit (9) of the dividend behind the 373 and repeat the process: 3739 / 640

Step 8:
3739 divided by 640 is 5 with a remainder of 539.
Put 5 as the next digit of the answer. 
Result so far: 135485.0
Subtracting 3200 from 3739 leaves us with 539.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5390, and continue the process.

Going ahead to step 9:
When dividing 5390 by 640, we get 8 with a remainder of 270.
The number 8 becomes the next digit in our result. 
Result so far: 135485.8
Subtract 5120 from 5390 to get 270.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2700, and continue the process.

Going ahead to step 10:
When dividing 2700 by 640, we get 4 with a remainder of 140.
Write down 4 as next digit of the result. 
Result so far: 135485.84
If we subtract 2560 from 2700, we get 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Step 11:
640 goes into 1400 2 times with a remainder of 120.
Write down 2 as next digit of the result. 
Result so far: 135485.842
If we subtract 1280 from 1400, we get 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Moving on to step 12:
640 can be fit into 1200 1 times, resulting in a remainder of 560.
Put 1 as the next digit of the answer. 
Result so far: 135485.8421
Subtracting 640 from 1200 leaves us with 560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5600, and continue the process.

Advancing to step 13:
The number 640 fits into 5600 8 times, leaving a remainder of 480.
Write down 8 as next digit of the result. 
Result so far: 135485.84218
The remainder is 480 after subtracting 5120 from 5600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

Let's proceed to step 14:
640 can be fit into 4800 7 times, resulting in a remainder of 320.
Write down 7 as next digit of the result. 
Result so far: 135485.842187
Subtracting 4480 from 4800 leaves us with 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Going ahead to step 15:
640 can be fit into 3200 5 times, resulting in a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 135485.8421875
Deduct 3200 from 3200 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 16:
The number 640 fits into 0 0 times, leaving a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 135485.8421875
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 135485.8421875 and a remainder of 0.0.