We look at the division of 421670 by 66 
The aim is to understand the frequency of 66 in 421670.

Moving on to step 1:
4 divided by 66 is 0 with a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 66

Going ahead to step 2:
66 can be fit into 42 0 times, resulting in a remainder of 42.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we subtract 0 from 42, we get 42.
Bring next digit (1) of the dividend behind the 42 and repeat the process: 421 / 66

Let's proceed to step 3:
66 can be fit into 421 6 times, resulting in a remainder of 25.
Put 6 as the next digit of the answer. 
Result so far: 6.0
Deduct 396 from 421 and we're left with 25.
Fetch the next digit (6) from the dividend, attach it to 25 and continue: 256 / 66

Going ahead to step 4:
66 goes into 256 3 times with a remainder of 58.
The number 3 becomes the next digit in our result. 
Result so far: 63.0
Subtracting 198 from 256 leaves us with 58.
Fetch the next digit (7) from the dividend, attach it to 58 and continue: 587 / 66

Going ahead to step 5:
If we divide 587 by 66, we get 8 and a remainder of 59.
Record the quotient 8 as the next digit in the result. 
Result so far: 638.0
If we take 528 away from 587, we end up with 59.
Grab the next digit (0) from the dividend, add it to 59, then carry on: 590 / 66

Going ahead to step 6:
If we divide 590 by 66, we get 8 and a remainder of 62.
The next digit of our result is 8. 
Result so far: 6388.0
Subtracting 528 from 590 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.

Advancing to step 7:
When dividing 620 by 66, we get 9 with a remainder of 26.
Put 9 as the next digit of the answer. 
Result so far: 6388.9
Deduct 594 from 620 and we're left 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.

On to step 8:
If we divide 260 by 66, we get 3 and a remainder of 62.
Put 3 as the next digit of the answer. 
Result so far: 6388.93
Deduct 198 from 260 and we're left 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 9:
When dividing 620 by 66, we get 9 with a remainder of 26.
The number 9 becomes the next digit in our result. 
Result so far: 6388.939
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.

Let's proceed to step 10:
66 can be fit into 260 3 times, resulting in a remainder of 62.
The next digit of our result is 3. 
Result so far: 6388.9393
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.

Let's proceed to step 11:
The number 66 fits into 620 9 times, leaving a remainder of 26.
Put 9 as the next digit of the answer. 
Result so far: 6388.93939
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.

Going ahead to step 12:
When dividing 260 by 66, we get 3 with a remainder of 62.
Use 3 as the next digit of our solution. 
Result so far: 6388.939393
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 13:
If we divide 620 by 66, we get 9 and a remainder of 26.
Put 9 as the next digit of the answer. 
Result so far: 6388.9393939
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.

Going ahead to step 14:
66 goes into 260 3 times with a remainder of 62.
Write down 3 as next digit of the result. 
Result so far: 6388.93939393
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.

The quotient of the division is 6388.93939393, and the remainder is 6.2e-08.