251786 divided by 66 
The aim is to understand the frequency of 66 in 251786.

On to step 1:
2 divided by 66 is 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 66

Moving on to step 2:
66 can be fit into 25 0 times, resulting in a remainder of 25.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 25 after subtracting 0 from 25.
Take the next digit (1) from the dividend and append it to 25, then repeat: 251 / 66

Advancing to step 3:
66 goes into 251 3 times with a remainder of 53.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 198 from 251 leaves us with 53.
Take the next digit (7) from the dividend and append it to 53, then repeat: 537 / 66

Advancing to step 4:
The number 66 fits into 537 8 times, leaving a remainder of 9.
The next digit of our result is 8. 
Result so far: 38.0
If we subtract 528 from 537, we get 9.
Take the next digit (8) from the dividend and append it to 9, then repeat: 98 / 66

Moving on to step 5:
The number 66 fits into 98 1 times, leaving a remainder of 32.
Use 1 as the next digit of our solution. 
Result so far: 381.0
Deduct 66 from 98 and we're left with 32.
Take the next digit (6) from the dividend and append it to 32, then repeat: 326 / 66

Advancing to step 6:
If we divide 326 by 66, we get 4 and a remainder of 62.
Put 4 as the next digit of the answer. 
Result so far: 3814.0
The remainder is 62 after subtracting 264 from 326.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Moving on to step 7:
66 can be fit into 620 9 times, resulting in a remainder of 26.
The next digit of our result is 9. 
Result so far: 3814.9
Subtracting 594 from 620 leaves us with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Advancing to step 8:
If we divide 260 by 66, we get 3 and a remainder of 62.
Use 3 as the next digit of our solution. 
Result so far: 3814.93
Subtracting 198 from 260 leaves us with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

On to step 9:
620 divided by 66 is 9 with a remainder of 26.
Record the quotient 9 as the next digit in the result. 
Result so far: 3814.939
The remainder is 26 after subtracting 594 from 620.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Let's proceed to step 10:
66 goes into 260 3 times with a remainder of 62.
Use 3 as the next digit of our solution. 
Result so far: 3814.9393
Subtracting 198 from 260 leaves us with 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Step 11:
The number 66 fits into 620 9 times, leaving a remainder of 26.
The number 9 becomes the next digit in our result. 
Result so far: 3814.93939
If we subtract 594 from 620, we get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Moving on to step 12:
66 can be fit into 260 3 times, resulting in a remainder of 62.
Record the quotient 3 as the next digit in the result. 
Result so far: 3814.939393
The remainder is 62 after subtracting 198 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 13:
When dividing 620 by 66, we get 9 with a remainder of 26.
Record the quotient 9 as the next digit in the result. 
Result so far: 3814.9393939
Subtract 594 from 620 to get 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

Step 14:
66 can be fit into 260 3 times, resulting in a remainder of 62.
Write down 3 as next digit of the result. 
Result so far: 3814.93939393
The remainder is 62 after subtracting 198 from 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

After the division, we end up with 3814.93939393 and a remainder of 6.2e-08.