We look at the division of 78786354 by 648 
We want to figure out the number of times 78786354 can be divided by 648.

Let's proceed to step 1:
The number 648 fits into 7 0 times, leaving a remainder of 7.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Take the next digit (8) from the dividend and append it to 7, then repeat: 78 / 648

Let's proceed to step 2:
If we divide 78 by 648, we get 0 and a remainder of 78.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 78 and we're left with 78.
Append the next digit (7) from the dividend to 78 and continue with: 787 / 648

Going ahead to step 3:
The number 648 fits into 787 1 times, leaving a remainder of 139.
Write down 1 as next digit of the result. 
Result so far: 1.0
The remainder is 139 after subtracting 648 from 787.
Include the next digit (8) from the dividend after 139, then repeat: 1398 / 648

Moving on to step 4:
When dividing 1398 by 648, we get 2 with a remainder of 102.
Put 2 as the next digit of the answer. 
Result so far: 12.0
Subtract 1296 from 1398 to get 102.
Append the next digit (6) from the dividend to 102 and continue with: 1026 / 648

Advancing to step 5:
The number 648 fits into 1026 1 times, leaving a remainder of 378.
Use 1 as the next digit of our solution. 
Result so far: 121.0
Subtract 648 from 1026 to get 378.
Grab the next digit (3) from the dividend, add it to 378, then carry on: 3783 / 648

Going ahead to step 6:
3783 divided by 648 is 5 with a remainder of 543.
Record the quotient 5 as the next digit in the result. 
Result so far: 1215.0
The remainder is 543 after subtracting 3240 from 3783.
Bring next digit (5) of the dividend behind the 543 and repeat the process: 5435 / 648

Moving on to step 7:
648 can be fit into 5435 8 times, resulting in a remainder of 251.
The next digit of our result is 8. 
Result so far: 12158.0
Subtract 5184 from 5435 to get 251.
Take the next digit (4) from the dividend and append it to 251, then repeat: 2514 / 648

Advancing to step 8:
The number 648 fits into 2514 3 times, leaving a remainder of 570.
Write down 3 as next digit of the result. 
Result so far: 121583.0
Deduct 1944 from 2514 and we're left with 570.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5700, and continue the process.

Advancing to step 9:
5700 divided by 648 is 8 with a remainder of 516.
Record the quotient 8 as the next digit in the result. 
Result so far: 121583.8
The remainder is 516 after subtracting 5184 from 5700.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5160, and continue the process.

Advancing to step 10:
The number 648 fits into 5160 7 times, leaving a remainder of 624.
The next digit of our result is 7. 
Result so far: 121583.87
Deduct 4536 from 5160 and we're left with 624.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6240, and continue the process.

On to step 11:
When dividing 6240 by 648, we get 9 with a remainder of 408.
Put 9 as the next digit of the answer. 
Result so far: 121583.879
The remainder is 408 after subtracting 5832 from 6240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

Step 12:
648 can be fit into 4080 6 times, resulting in a remainder of 192.
Write down 6 as next digit of the result. 
Result so far: 121583.8796
The remainder is 192 after subtracting 3888 from 4080.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1920, and continue the process.

Going ahead to step 13:
When dividing 1920 by 648, we get 2 with a remainder of 624.
Record the quotient 2 as the next digit in the result. 
Result so far: 121583.87962
Subtracting 1296 from 1920 leaves us with 624.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6240, and continue the process.

Advancing to step 14:
If we divide 6240 by 648, we get 9 and a remainder of 408.
The next digit of our result is 9. 
Result so far: 121583.879629
Subtracting 5832 from 6240 leaves us with 408.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4080, and continue the process.

Moving on to step 15:
648 goes into 4080 6 times with a remainder of 192.
Use 6 as the next digit of our solution. 
Result so far: 121583.8796296
Subtract 3888 from 4080 to get 192.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1920, and continue the process.

Advancing to step 16:
1920 divided by 648 is 2 with a remainder of 624.
The number 2 becomes the next digit in our result. 
Result so far: 121583.87962962
If we take 1296 away from 1920, we end up with 624.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6240, and continue the process.

The final outcome is 121583.87962962, with a leftover of 6.24e-07.