60170988 divided by 645 
The aim is to understand the frequency of 645 in 60170988.

Going ahead to step 1:
When dividing 6 by 645, we get 0 with a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 6 leaves us with 6.
Take the next digit (0) from the dividend and append it to 6, then repeat: 60 / 645

Moving on to step 2:
When dividing 60 by 645, we get 0 with a remainder of 60.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 60 to get 60.
Include the next digit (1) from the dividend after 60, then repeat: 601 / 645

Going ahead to step 3:
601 divided by 645 is 0 with a remainder of 601.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 601 and we're left with 601.
Grab the next digit (7) from the dividend, add it to 601, then carry on: 6017 / 645

On to step 4:
6017 divided by 645 is 9 with a remainder of 212.
Write down 9 as next digit of the result. 
Result so far: 9.0
If we subtract 5805 from 6017, we get 212.
Include the next digit (0) from the dividend after 212, then repeat: 2120 / 645

Let's proceed to step 5:
When dividing 2120 by 645, we get 3 with a remainder of 185.
Record the quotient 3 as the next digit in the result. 
Result so far: 93.0
If we take 1935 away from 2120, we end up with 185.
Append the next digit (9) from the dividend to 185 and continue with: 1859 / 645

Moving on to step 6:
1859 divided by 645 is 2 with a remainder of 569.
The next digit of our result is 2. 
Result so far: 932.0
Subtract 1290 from 1859 to get 569.
Include the next digit (8) from the dividend after 569, then repeat: 5698 / 645

Moving on to step 7:
645 goes into 5698 8 times with a remainder of 538.
The next digit of our result is 8. 
Result so far: 9328.0
The remainder is 538 after subtracting 5160 from 5698.
Grab the next digit (8) from the dividend, add it to 538, then carry on: 5388 / 645

On to step 8:
5388 divided by 645 is 8 with a remainder of 228.
Record the quotient 8 as the next digit in the result. 
Result so far: 93288.0
If we subtract 5160 from 5388, we get 228.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2280, and continue the process.

On to step 9:
The number 645 fits into 2280 3 times, leaving a remainder of 345.
The number 3 becomes the next digit in our result. 
Result so far: 93288.3
Subtracting 1935 from 2280 leaves us with 345.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3450, and continue the process.

Step 10:
If we divide 3450 by 645, we get 5 and a remainder of 225.
Use 5 as the next digit of our solution. 
Result so far: 93288.35
Subtracting 3225 from 3450 leaves us with 225.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2250, and continue the process.

Moving on to step 11:
2250 divided by 645 is 3 with a remainder of 315.
Record the quotient 3 as the next digit in the result. 
Result so far: 93288.353
The remainder is 315 after subtracting 1935 from 2250.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3150, and continue the process.

Step 12:
When dividing 3150 by 645, we get 4 with a remainder of 570.
Put 4 as the next digit of the answer. 
Result so far: 93288.3534
Subtracting 2580 from 3150 leaves us with 570.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5700, and continue the process.

Going ahead to step 13:
645 can be fit into 5700 8 times, resulting in a remainder of 540.
Use 8 as the next digit of our solution. 
Result so far: 93288.35348
If we take 5160 away from 5700, we end up with 540.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5400, and continue the process.

Let's proceed to step 14:
The number 645 fits into 5400 8 times, leaving a remainder of 240.
The number 8 becomes the next digit in our result. 
Result so far: 93288.353488
If we take 5160 away from 5400, 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.

The final outcome is 93288.353488, with a leftover of 2.4e-05.