We look at the division of 668641 by 54 
The aim is to understand the frequency of 54 in 668641.

On to step 1:
When dividing 6 by 54, we get 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 54

Advancing to step 2:
If we divide 66 by 54, we get 1 and a remainder of 12.
Record the quotient 1 as the next digit in the result. 
Result so far: 1.0
Subtracting 54 from 66 leaves us with 12.
Fetch the next digit (8) from the dividend, attach it to 12 and continue: 128 / 54

On to step 3:
When dividing 128 by 54, we get 2 with a remainder of 20.
The number 2 becomes the next digit in our result. 
Result so far: 12.0
If we take 108 away from 128, we end up with 20.
Append the next digit (6) from the dividend to 20 and continue with: 206 / 54

Advancing to step 4:
54 goes into 206 3 times with a remainder of 44.
The next digit of our result is 3. 
Result so far: 123.0
If we subtract 162 from 206, we get 44.
Grab the next digit (4) from the dividend, add it to 44, then carry on: 444 / 54

Let's proceed to step 5:
54 can be fit into 444 8 times, resulting in a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 1238.0
Subtract 432 from 444 to get 12.
Fetch the next digit (1) from the dividend, attach it to 12 and continue: 121 / 54

Step 6:
If we divide 121 by 54, we get 2 and a remainder of 13.
Record the quotient 2 as the next digit in the result. 
Result so far: 12382.0
If we subtract 108 from 121, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 7:
When dividing 130 by 54, we get 2 with a remainder of 22.
Record the quotient 2 as the next digit in the result. 
Result so far: 12382.2
If we take 108 away from 130, we end up with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Moving on to step 8:
54 goes into 220 4 times with a remainder of 4.
Record the quotient 4 as the next digit in the result. 
Result so far: 12382.24
Deduct 216 from 220 and we're left 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.

On to step 9:
If we divide 40 by 54, we get 0 and a remainder of 40.
Record the quotient 0 as the next digit in the result. 
Result so far: 12382.24
Deduct 0 from 40 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Let's proceed to step 10:
54 can be fit into 400 7 times, resulting in a remainder of 22.
Record the quotient 7 as the next digit in the result. 
Result so far: 12382.2407
If we take 378 away from 400, we end up with 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

Let's proceed to step 11:
When dividing 220 by 54, we get 4 with a remainder of 4.
Use 4 as the next digit of our solution. 
Result so far: 12382.24074
Subtracting 216 from 220 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.

Going ahead to step 12:
If we divide 40 by 54, we get 0 and a remainder of 40.
The number 0 becomes the next digit in our result. 
Result so far: 12382.24074
Deduct 0 from 40 and we're left with 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

On to step 13:
54 can be fit into 400 7 times, resulting in a remainder of 22.
Use 7 as the next digit of our solution. 
Result so far: 12382.2407407
Subtract 378 from 400 to get 22.
Since there are no more digits in the dividend, we add a zero to the remainder making it 220, and continue the process.

On to step 14:
When dividing 220 by 54, we get 4 with a remainder of 4.
Record the quotient 4 as the next digit in the result. 
Result so far: 12382.24074074
If we subtract 216 from 220, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

In conclusion, the division gives 12382.24074074 with a balance of 4e-09.