646668 ÷ 13 
We want to figure out the number of times 646668 can be divided by 13.

On to step 1:
13 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 13

Step 2:
13 can be fit into 64 4 times, resulting in a remainder of 12.
Put 4 as the next digit of the answer. 
Result so far: 4.0
If we subtract 52 from 64, we get 12.
Grab the next digit (6) from the dividend, add it to 12, then carry on: 126 / 13

Step 3:
13 can be fit into 126 9 times, resulting in a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 49.0
If we take 117 away from 126, we end up with 9.
Take the next digit (6) from the dividend and append it to 9, then repeat: 96 / 13

Step 4:
The number 13 fits into 96 7 times, leaving a remainder of 5.
Put 7 as the next digit of the answer. 
Result so far: 497.0
Deduct 91 from 96 and we're left with 5.
Fetch the next digit (6) from the dividend, attach it to 5 and continue: 56 / 13

Step 5:
13 can be fit into 56 4 times, resulting in a remainder of 4.
The number 4 becomes the next digit in our result. 
Result so far: 4974.0
Subtract 52 from 56 to get 4.
Grab the next digit (8) from the dividend, add it to 4, then carry on: 48 / 13

Let's proceed to step 6:
When dividing 48 by 13, we get 3 with a remainder of 9.
Put 3 as the next digit of the answer. 
Result so far: 49743.0
If we take 39 away from 48, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 7:
If we divide 90 by 13, we get 6 and a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 49743.6
If we subtract 78 from 90, we get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Let's proceed to step 8:
The number 13 fits into 120 9 times, leaving a remainder of 3.
Use 9 as the next digit of our solution. 
Result so far: 49743.69
The remainder is 3 after subtracting 117 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 9:
If we divide 30 by 13, we get 2 and a remainder of 4.
Use 2 as the next digit of our solution. 
Result so far: 49743.692
Subtracting 26 from 30 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 10:
If we divide 40 by 13, we get 3 and a remainder of 1.
Use 3 as the next digit of our solution. 
Result so far: 49743.6923
Subtracting 39 from 40 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
10 divided by 13 is 0 with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 49743.6923
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 12:
100 divided by 13 is 7 with a remainder of 9.
Write down 7 as next digit of the result. 
Result so far: 49743.692307
Deduct 91 from 100 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Step 13:
When dividing 90 by 13, we get 6 with a remainder of 12.
Record the quotient 6 as the next digit in the result. 
Result so far: 49743.6923076
Deduct 78 from 90 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

Advancing to step 14:
The number 13 fits into 120 9 times, leaving a remainder of 3.
Use 9 as the next digit of our solution. 
Result so far: 49743.69230769
Subtract 117 from 120 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

After the division, we end up with 49743.69230769 and a remainder of 3e-09.