54872123 divided by 646 
We want to figure out the number of times 54872123 can be divided by 646.

Going ahead to step 1:
When dividing 5 by 646, we get 0 with a remainder of 5.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Append the next digit (4) from the dividend to 5 and continue with: 54 / 646

Advancing to step 2:
When dividing 54 by 646, we get 0 with a remainder of 54.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 54, we get 54.
Fetch the next digit (8) from the dividend, attach it to 54 and continue: 548 / 646

On to step 3:
646 goes into 548 0 times with a remainder of 548.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 548 and we're left with 548.
Include the next digit (7) from the dividend after 548, then repeat: 5487 / 646

Going ahead to step 4:
The number 646 fits into 5487 8 times, leaving a remainder of 319.
Record the quotient 8 as the next digit in the result. 
Result so far: 8.0
If we take 5168 away from 5487, we end up with 319.
Include the next digit (2) from the dividend after 319, then repeat: 3192 / 646

Let's proceed to step 5:
646 goes into 3192 4 times with a remainder of 608.
Put 4 as the next digit of the answer. 
Result so far: 84.0
The remainder is 608 after subtracting 2584 from 3192.
Fetch the next digit (1) from the dividend, attach it to 608 and continue: 6081 / 646

Let's proceed to step 6:
If we divide 6081 by 646, we get 9 and a remainder of 267.
The number 9 becomes the next digit in our result. 
Result so far: 849.0
The remainder is 267 after subtracting 5814 from 6081.
Include the next digit (2) from the dividend after 267, then repeat: 2672 / 646

On to step 7:
If we divide 2672 by 646, we get 4 and a remainder of 88.
Put 4 as the next digit of the answer. 
Result so far: 8494.0
Deduct 2584 from 2672 and we're left with 88.
Include the next digit (3) from the dividend after 88, then repeat: 883 / 646

Going ahead to step 8:
When dividing 883 by 646, we get 1 with a remainder of 237.
Record the quotient 1 as the next digit in the result. 
Result so far: 84941.0
Subtract 646 from 883 to get 237.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2370, and continue the process.

Moving on to step 9:
646 can be fit into 2370 3 times, resulting in a remainder of 432.
The number 3 becomes the next digit in our result. 
Result so far: 84941.3
Subtract 1938 from 2370 to get 432.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4320, and continue the process.

Moving on to step 10:
The number 646 fits into 4320 6 times, leaving a remainder of 444.
Use 6 as the next digit of our solution. 
Result so far: 84941.36
If we subtract 3876 from 4320, we get 444.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4440, and continue the process.

Advancing to step 11:
When dividing 4440 by 646, we get 6 with a remainder of 564.
Write down 6 as next digit of the result. 
Result so far: 84941.366
Deduct 3876 from 4440 and we're left with 564.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5640, and continue the process.

After the division, we end up with 84941.366 and a remainder of 0.0564.