14923086 ÷ 645 
The aim is to understand the frequency of 645 in 14923086.

Step 1:
If we divide 1 by 645, we get 0 and a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (4) from the dividend to 1 and continue with: 14 / 645

On to step 2:
The number 645 fits into 14 0 times, leaving a remainder of 14.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 14, we get 14.
Include the next digit (9) from the dividend after 14, then repeat: 149 / 645

Moving on to step 3:
When dividing 149 by 645, we get 0 with a remainder of 149.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 149 after subtracting 0 from 149.
Fetch the next digit (2) from the dividend, attach it to 149 and continue: 1492 / 645

Let's proceed to step 4:
When dividing 1492 by 645, we get 2 with a remainder of 202.
Write down 2 as next digit of the result. 
Result so far: 2.0
Deduct 1290 from 1492 and we're left with 202.
Bring next digit (3) of the dividend behind the 202 and repeat the process: 2023 / 645

Advancing to step 5:
2023 divided by 645 is 3 with a remainder of 88.
The next digit of our result is 3. 
Result so far: 23.0
The remainder is 88 after subtracting 1935 from 2023.
Take the next digit (0) from the dividend and append it to 88, then repeat: 880 / 645

Going ahead to step 6:
645 goes into 880 1 times with a remainder of 235.
Put 1 as the next digit of the answer. 
Result so far: 231.0
If we subtract 645 from 880, we get 235.
Append the next digit (8) from the dividend to 235 and continue with: 2358 / 645

On to step 7:
The number 645 fits into 2358 3 times, leaving a remainder of 423.
Use 3 as the next digit of our solution. 
Result so far: 2313.0
If we subtract 1935 from 2358, we get 423.
Grab the next digit (6) from the dividend, add it to 423, then carry on: 4236 / 645

Advancing to step 8:
The number 645 fits into 4236 6 times, leaving a remainder of 366.
Record the quotient 6 as the next digit in the result. 
Result so far: 23136.0
Subtracting 3870 from 4236 leaves us with 366.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3660, and continue the process.

Moving on to step 9:
645 goes into 3660 5 times with a remainder of 435.
The next digit of our result is 5. 
Result so far: 23136.5
Subtract 3225 from 3660 to get 435.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4350, and continue the process.

Let's proceed to step 10:
The number 645 fits into 4350 6 times, leaving a remainder of 480.
Write down 6 as next digit of the result. 
Result so far: 23136.56
The remainder is 480 after subtracting 3870 from 4350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4800, and continue the process.

Moving on to step 11:
645 can be fit into 4800 7 times, resulting in a remainder of 285.
Write down 7 as next digit of the result. 
Result so far: 23136.567
Deduct 4515 from 4800 and we're left with 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Advancing to step 12:
645 can be fit into 2850 4 times, resulting in a remainder of 270.
Write down 4 as next digit of the result. 
Result so far: 23136.5674
The remainder is 270 after subtracting 2580 from 2850.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2700, and continue the process.

Step 13:
645 can be fit into 2700 4 times, resulting in a remainder of 120.
Use 4 as the next digit of our solution. 
Result so far: 23136.56744
If we take 2580 away from 2700, we end up with 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

The quotient of the division is 23136.56744, and the remainder is 0.00012.