We're dividing 18569949 by 648 
The aim is to understand the frequency of 648 in 18569949.

On to step 1:
When dividing 1 by 648, we get 0 with a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Fetch the next digit (8) from the dividend, attach it to 1 and continue: 18 / 648

Advancing to step 2:
648 can be fit into 18 0 times, resulting in a remainder of 18.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 18 to get 18.
Append the next digit (5) from the dividend to 18 and continue with: 185 / 648

Going ahead to step 3:
When dividing 185 by 648, we get 0 with a remainder of 185.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 185 to get 185.
Include the next digit (6) from the dividend after 185, then repeat: 1856 / 648

Going ahead to step 4:
1856 divided by 648 is 2 with a remainder of 560.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtracting 1296 from 1856 leaves us with 560.
Bring next digit (9) of the dividend behind the 560 and repeat the process: 5609 / 648

On to step 5:
When dividing 5609 by 648, we get 8 with a remainder of 425.
The next digit of our result is 8. 
Result so far: 28.0
Subtracting 5184 from 5609 leaves us with 425.
Bring next digit (9) of the dividend behind the 425 and repeat the process: 4259 / 648

Advancing to step 6:
If we divide 4259 by 648, we get 6 and a remainder of 371.
The next digit of our result is 6. 
Result so far: 286.0
Deduct 3888 from 4259 and we're left with 371.
Append the next digit (4) from the dividend to 371 and continue with: 3714 / 648

Step 7:
When dividing 3714 by 648, we get 5 with a remainder of 474.
Record the quotient 5 as the next digit in the result. 
Result so far: 2865.0
The remainder is 474 after subtracting 3240 from 3714.
Include the next digit (9) from the dividend after 474, then repeat: 4749 / 648

Going ahead to step 8:
The number 648 fits into 4749 7 times, leaving a remainder of 213.
Record the quotient 7 as the next digit in the result. 
Result so far: 28657.0
Subtracting 4536 from 4749 leaves us with 213.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2130, and continue the process.

Step 9:
648 can be fit into 2130 3 times, resulting in a remainder of 186.
The next digit of our result is 3. 
Result so far: 28657.3
Subtract 1944 from 2130 to get 186.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1860, and continue the process.

On to step 10:
648 can be fit into 1860 2 times, resulting in a remainder of 564.
Put 2 as the next digit of the answer. 
Result so far: 28657.32
The remainder is 564 after subtracting 1296 from 1860.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5640, and continue the process.

Moving on to step 11:
648 can be fit into 5640 8 times, resulting in a remainder of 456.
Write down 8 as next digit of the result. 
Result so far: 28657.328
If we subtract 5184 from 5640, we get 456.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4560, and continue the process.

Advancing to step 12:
648 goes into 4560 7 times with a remainder of 24.
Write down 7 as next digit of the result. 
Result so far: 28657.3287
Subtracting 4536 from 4560 leaves us with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Going ahead to step 13:
When dividing 240 by 648, we get 0 with a remainder of 240.
The next digit of our result is 0. 
Result so far: 28657.3287
If we take 0 away from 240, we end up with 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

Going ahead to step 14:
648 goes into 2400 3 times with a remainder of 456.
Put 3 as the next digit of the answer. 
Result so far: 28657.328703
The remainder is 456 after subtracting 1944 from 2400.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4560, and continue the process.

Going ahead to step 15:
If we divide 4560 by 648, we get 7 and a remainder of 24.
Record the quotient 7 as the next digit in the result. 
Result so far: 28657.3287037
Subtracting 4536 from 4560 leaves us with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Let's proceed to step 16:
When dividing 240 by 648, we get 0 with a remainder of 240.
Use 0 as the next digit of our solution. 
Result so far: 28657.3287037
Subtract 0 from 240 to get 240.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2400, and continue the process.

The quotient of the division is 28657.3287037, and the remainder is 2.4e-07.