12387186 ÷ 666 
We're looking to find how many times 666 goes into 12387186.

Let's proceed to step 1:
1 divided by 666 is 0 with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 666

Advancing to step 2:
12 divided by 666 is 0 with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 12 to get 12.
Fetch the next digit (3) from the dividend, attach it to 12 and continue: 123 / 666

Advancing to step 3:
When dividing 123 by 666, we get 0 with a remainder of 123.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 123, we get 123.
Take the next digit (8) from the dividend and append it to 123, then repeat: 1238 / 666

Moving on to step 4:
666 goes into 1238 1 times with a remainder of 572.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
The remainder is 572 after subtracting 666 from 1238.
Fetch the next digit (7) from the dividend, attach it to 572 and continue: 5727 / 666

Going ahead to step 5:
5727 divided by 666 is 8 with a remainder of 399.
The number 8 becomes the next digit in our result. 
Result so far: 18.0
The remainder is 399 after subtracting 5328 from 5727.
Take the next digit (1) from the dividend and append it to 399, then repeat: 3991 / 666

Let's proceed to step 6:
666 goes into 3991 5 times with a remainder of 661.
Use 5 as the next digit of our solution. 
Result so far: 185.0
If we take 3330 away from 3991, we end up with 661.
Fetch the next digit (8) from the dividend, attach it to 661 and continue: 6618 / 666

Advancing to step 7:
If we divide 6618 by 666, we get 9 and a remainder of 624.
Write down 9 as next digit of the result. 
Result so far: 1859.0
If we take 5994 away from 6618, we end up with 624.
Fetch the next digit (6) from the dividend, attach it to 624 and continue: 6246 / 666

Moving on to step 8:
6246 divided by 666 is 9 with a remainder of 252.
The next digit of our result is 9. 
Result so far: 18599.0
Subtracting 5994 from 6246 leaves us with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

Moving on to step 9:
When dividing 2520 by 666, we get 3 with a remainder of 522.
Record the quotient 3 as the next digit in the result. 
Result so far: 18599.3
Subtract 1998 from 2520 to get 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

Going ahead to step 10:
5220 divided by 666 is 7 with a remainder of 558.
The number 7 becomes the next digit in our result. 
Result so far: 18599.37
If we subtract 4662 from 5220, we get 558.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5580, and continue the process.

On to step 11:
The number 666 fits into 5580 8 times, leaving a remainder of 252.
Write down 8 as next digit of the result. 
Result so far: 18599.378
Subtracting 5328 from 5580 leaves us with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

On to step 12:
2520 divided by 666 is 3 with a remainder of 522.
The number 3 becomes the next digit in our result. 
Result so far: 18599.3783
Deduct 1998 from 2520 and we're left with 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

Advancing to step 13:
5220 divided by 666 is 7 with a remainder of 558.
The next digit of our result is 7. 
Result so far: 18599.37837
Subtract 4662 from 5220 to get 558.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5580, and continue the process.

On to step 14:
When dividing 5580 by 666, we get 8 with a remainder of 252.
The next digit of our result is 8. 
Result so far: 18599.378378
If we take 5328 away from 5580, we end up with 252.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2520, and continue the process.

Advancing to step 15:
When dividing 2520 by 666, we get 3 with a remainder of 522.
Write down 3 as next digit of the result. 
Result so far: 18599.3783783
If we subtract 1998 from 2520, we get 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

On to step 16:
If we divide 5220 by 666, we get 7 and a remainder of 558.
The next digit of our result is 7. 
Result so far: 18599.37837837
Deduct 4662 from 5220 and we're left with 558.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5580, and continue the process.

The final outcome is 18599.37837837, with a leftover of 5.58e-07.