We divide 78511966 by 20
Our goal is to divide 78511966 by 20.

On to step 1:
20 can be fit into 7 0 times, resulting in a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Grab the next digit (8) from the dividend, add it to 7, then carry on: 78 / 20

Step 2:
20 goes into 78 3 times with a remainder of 18.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtract 60 from 78 to get 18.
Fetch the next digit (5) from the dividend, attach it to 18 and continue: 185 / 20

Step 3:
The number 20 fits into 185 9 times, leaving a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 39.0
If we subtract 180 from 185, we get 5.
Include the next digit (1) from the dividend after 5, then repeat: 51 / 20

Advancing to step 4:
20 goes into 51 2 times with a remainder of 11.
Use 2 as the next digit of our solution. 
Result so far: 392.0
The remainder is 11 after subtracting 40 from 51.
Grab the next digit (1) from the dividend, add it to 11, then carry on: 111 / 20

Step 5:
The number 20 fits into 111 5 times, leaving a remainder of 11.
Put 5 as the next digit of the answer. 
Result so far: 3925.0
The remainder is 11 after subtracting 100 from 111.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 20

On to step 6:
119 divided by 20 is 5 with a remainder of 19.
Use 5 as the next digit of our solution. 
Result so far: 39255.0
Deduct 100 from 119 and we're left with 19.
Fetch the next digit (6) from the dividend, attach it to 19 and continue: 196 / 20

On to step 7:
20 goes into 196 9 times with a remainder of 16.
The number 9 becomes the next digit in our result. 
Result so far: 392559.0
Deduct 180 from 196 and we're left with 16.
Fetch the next digit (6) from the dividend, attach it to 16 and continue: 166 / 20

Advancing to step 8:
166 divided by 20 is 8 with a remainder of 6.
The next digit of our result is 8. 
Result so far: 3925598.0
If we take 160 away from 166, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 9:
When dividing 60 by 20, we get 3 with a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 3925598.3
If we take 60 away from 60, we end up 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 10:
0 divided by 20 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 3925598.3
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.

Going ahead to step 11:
20 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 3925598.3
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.

The final result is 3925598.3 with a remainder of 0.0.