78555142 divided by 80 
We're looking to find how many times 80 goes into 78555142.

Advancing to step 1:
80 can be fit into 7 0 times, resulting in a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 7 and we're left with 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 80

Advancing to step 2:
80 goes into 78 0 times with a remainder of 78.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 78, we get 78.
Grab the next digit (5) from the dividend, add it to 78, then carry on: 785 / 80

On to step 3:
80 can be fit into 785 9 times, resulting in a remainder of 65.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
Subtracting 720 from 785 leaves us with 65.
Bring next digit (5) of the dividend behind the 65 and repeat the process: 655 / 80

On to step 4:
When dividing 655 by 80, we get 8 with a remainder of 15.
The number 8 becomes the next digit in our result. 
Result so far: 98.0
Subtract 640 from 655 to get 15.
Take the next digit (5) from the dividend and append it to 15, then repeat: 155 / 80

Going ahead to step 5:
The number 80 fits into 155 1 times, leaving a remainder of 75.
Put 1 as the next digit of the answer. 
Result so far: 981.0
Deduct 80 from 155 and we're left with 75.
Fetch the next digit (1) from the dividend, attach it to 75 and continue: 751 / 80

Moving on to step 6:
80 goes into 751 9 times with a remainder of 31.
The number 9 becomes the next digit in our result. 
Result so far: 9819.0
Subtracting 720 from 751 leaves us with 31.
Include the next digit (4) from the dividend after 31, then repeat: 314 / 80

Let's proceed to step 7:
If we divide 314 by 80, we get 3 and a remainder of 74.
The number 3 becomes the next digit in our result. 
Result so far: 98193.0
Subtracting 240 from 314 leaves us with 74.
Fetch the next digit (2) from the dividend, attach it to 74 and continue: 742 / 80

Advancing to step 8:
80 can be fit into 742 9 times, resulting in a remainder of 22.
The next digit of our result is 9. 
Result so far: 981939.0
If we subtract 720 from 742, we get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

On to step 9:
80 can be fit into 220 2 times, resulting in a remainder of 60.
Write down 2 as next digit of the result. 
Result so far: 981939.2
Subtracting 160 from 220 leaves us with 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Going ahead to step 10:
600 divided by 80 is 7 with a remainder of 40.
Use 7 as the next digit of our solution. 
Result so far: 981939.27
The remainder is 40 after subtracting 560 from 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Let's proceed to step 11:
When dividing 400 by 80, we get 5 with a remainder of 0.
The next digit of our result is 5. 
Result so far: 981939.275
Subtract 400 from 400 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 12:
If we divide 0 by 80, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 981939.275
Subtract 0 from 0 to get 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 13:
If we divide 0 by 80, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 981939.275
Deduct 0 from 0 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.

The final outcome is 981939.275, with a leftover of 0.0.