8088458 ÷ 640 
We want to figure out the number of times 8088458 can be divided by 640.

Step 1:
When dividing 8 by 640, we get 0 with a remainder of 8.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Bring next digit (0) of the dividend behind the 8 and repeat the process: 80 / 640

Advancing to step 2:
If we divide 80 by 640, we get 0 and a remainder of 80.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 80, we end up with 80.
Include the next digit (8) from the dividend after 80, then repeat: 808 / 640

Let's proceed to step 3:
640 goes into 808 1 times with a remainder of 168.
The next digit of our result is 1. 
Result so far: 1.0
If we take 640 away from 808, we end up with 168.
Append the next digit (8) from the dividend to 168 and continue with: 1688 / 640

Step 4:
1688 divided by 640 is 2 with a remainder of 408.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
Subtracting 1280 from 1688 leaves us with 408.
Append the next digit (4) from the dividend to 408 and continue with: 4084 / 640

Going ahead to step 5:
When dividing 4084 by 640, we get 6 with a remainder of 244.
Use 6 as the next digit of our solution. 
Result so far: 126.0
If we subtract 3840 from 4084, we get 244.
Bring next digit (5) of the dividend behind the 244 and repeat the process: 2445 / 640

Moving on to step 6:
640 can be fit into 2445 3 times, resulting in a remainder of 525.
The number 3 becomes the next digit in our result. 
Result so far: 1263.0
The remainder is 525 after subtracting 1920 from 2445.
Bring next digit (8) of the dividend behind the 525 and repeat the process: 5258 / 640

Advancing to step 7:
5258 divided by 640 is 8 with a remainder of 138.
Put 8 as the next digit of the answer. 
Result so far: 12638.0
Subtract 5120 from 5258 to get 138.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1380, and continue the process.

Going ahead to step 8:
640 goes into 1380 2 times with a remainder of 100.
Put 2 as the next digit of the answer. 
Result so far: 12638.2
If we subtract 1280 from 1380, we get 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1000, and continue the process.

Moving on to step 9:
1000 divided by 640 is 1 with a remainder of 360.
Use 1 as the next digit of our solution. 
Result so far: 12638.21
If we take 640 away from 1000, we end up with 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Going ahead to step 10:
The number 640 fits into 3600 5 times, leaving a remainder of 400.
Use 5 as the next digit of our solution. 
Result so far: 12638.215
The remainder is 400 after subtracting 3200 from 3600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4000, and continue the process.

Let's proceed to step 11:
If we divide 4000 by 640, we get 6 and a remainder of 160.
Write down 6 as next digit of the result. 
Result so far: 12638.2156
The remainder is 160 after subtracting 3840 from 4000.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Step 12:
When dividing 1600 by 640, we get 2 with a remainder of 320.
Record the quotient 2 as the next digit in the result. 
Result so far: 12638.21562
Deduct 1280 from 1600 and we're left 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.

Step 13:
3200 divided by 640 is 5 with a remainder of 0.
Write down 5 as next digit of the result. 
Result so far: 12638.215625
Subtracting 3200 from 3200 leaves us 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.

Going ahead to step 14:
The number 640 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 12638.215625
Subtracting 0 from 0 leaves us 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.

On to step 15:
0 divided by 640 is 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 12638.215625
Subtracting 0 from 0 leaves us 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.

The final outcome is 12638.215625, with a leftover of 0.0.