94538561 ÷ 648 
The aim is to understand the frequency of 648 in 94538561.

Moving on to step 1:
The number 648 fits into 9 0 times, leaving a remainder of 9.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 9 and we're left with 9.
Bring next digit (4) of the dividend behind the 9 and repeat the process: 94 / 648

Going ahead to step 2:
If we divide 94 by 648, we get 0 and a remainder of 94.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 94 after subtracting 0 from 94.
Grab the next digit (5) from the dividend, add it to 94, then carry on: 945 / 648

Advancing to step 3:
648 goes into 945 1 times with a remainder of 297.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 648 from 945 and we're left with 297.
Bring next digit (3) of the dividend behind the 297 and repeat the process: 2973 / 648

Moving on to step 4:
648 goes into 2973 4 times with a remainder of 381.
Use 4 as the next digit of our solution. 
Result so far: 14.0
Deduct 2592 from 2973 and we're left with 381.
Take the next digit (8) from the dividend and append it to 381, then repeat: 3818 / 648

Moving on to step 5:
The number 648 fits into 3818 5 times, leaving a remainder of 578.
The number 5 becomes the next digit in our result. 
Result so far: 145.0
Deduct 3240 from 3818 and we're left with 578.
Take the next digit (5) from the dividend and append it to 578, then repeat: 5785 / 648

Going ahead to step 6:
If we divide 5785 by 648, we get 8 and a remainder of 601.
Record the quotient 8 as the next digit in the result. 
Result so far: 1458.0
If we subtract 5184 from 5785, we get 601.
Fetch the next digit (6) from the dividend, attach it to 601 and continue: 6016 / 648

Let's proceed to step 7:
If we divide 6016 by 648, we get 9 and a remainder of 184.
The number 9 becomes the next digit in our result. 
Result so far: 14589.0
Subtracting 5832 from 6016 leaves us with 184.
Include the next digit (1) from the dividend after 184, then repeat: 1841 / 648

Going ahead to step 8:
1841 divided by 648 is 2 with a remainder of 545.
Put 2 as the next digit of the answer. 
Result so far: 145892.0
Subtracting 1296 from 1841 leaves us with 545.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5450, and continue the process.

Advancing to step 9:
When dividing 5450 by 648, we get 8 with a remainder of 266.
Use 8 as the next digit of our solution. 
Result so far: 145892.8
If we take 5184 away from 5450, we end up with 266.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2660, and continue the process.

Step 10:
If we divide 2660 by 648, we get 4 and a remainder of 68.
Use 4 as the next digit of our solution. 
Result so far: 145892.84
The remainder is 68 after subtracting 2592 from 2660.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

Going ahead to step 11:
When dividing 680 by 648, we get 1 with a remainder of 32.
The next digit of our result is 1. 
Result so far: 145892.841
If we subtract 648 from 680, we get 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Moving on to step 12:
320 divided by 648 is 0 with a remainder of 320.
The number 0 becomes the next digit in our result. 
Result so far: 145892.841
Subtract 0 from 320 to get 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Step 13:
The number 648 fits into 3200 4 times, leaving a remainder of 608.
The next digit of our result is 4. 
Result so far: 145892.84104
Deduct 2592 from 3200 and we're left with 608.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6080, and continue the process.

On to step 14:
If we divide 6080 by 648, we get 9 and a remainder of 248.
Write down 9 as next digit of the result. 
Result so far: 145892.841049
Subtracting 5832 from 6080 leaves us with 248.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2480, and continue the process.

Let's proceed to step 15:
648 goes into 2480 3 times with a remainder of 536.
Put 3 as the next digit of the answer. 
Result so far: 145892.8410493
If we subtract 1944 from 2480, we get 536.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5360, and continue the process.

Advancing to step 16:
The number 648 fits into 5360 8 times, leaving a remainder of 176.
Use 8 as the next digit of our solution. 
Result so far: 145892.84104938
If we take 5184 away from 5360, we end up with 176.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1760, and continue the process.

The final outcome is 145892.84104938, with a leftover of 1.76e-07.