12434687 divided by 405 
The aim is to understand the frequency of 405 in 12434687.

Advancing to step 1:
If we divide 1 by 405, we get 0 and a remainder of 1.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Include the next digit (2) from the dividend after 1, then repeat: 12 / 405

Let's proceed to step 2:
12 divided by 405 is 0 with a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 12 leaves us with 12.
Bring next digit (4) of the dividend behind the 12 and repeat the process: 124 / 405

Moving on to step 3:
The number 405 fits into 124 0 times, leaving a remainder of 124.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 124 leaves us with 124.
Fetch the next digit (3) from the dividend, attach it to 124 and continue: 1243 / 405

Moving on to step 4:
405 goes into 1243 3 times with a remainder of 28.
The number 3 becomes the next digit in our result. 
Result so far: 3.0
Subtract 1215 from 1243 to get 28.
Fetch the next digit (4) from the dividend, attach it to 28 and continue: 284 / 405

Let's proceed to step 5:
405 can be fit into 284 0 times, resulting in a remainder of 284.
Record the quotient 0 as the next digit in the result. 
Result so far: 30.0
If we subtract 0 from 284, we get 284.
Fetch the next digit (6) from the dividend, attach it to 284 and continue: 2846 / 405

Step 6:
405 can be fit into 2846 7 times, resulting in a remainder of 11.
Put 7 as the next digit of the answer. 
Result so far: 307.0
Subtract 2835 from 2846 to get 11.
Include the next digit (8) from the dividend after 11, then repeat: 118 / 405

On to step 7:
If we divide 118 by 405, we get 0 and a remainder of 118.
Put 0 as the next digit of the answer. 
Result so far: 3070.0
If we take 0 away from 118, we end up with 118.
Grab the next digit (7) from the dividend, add it to 118, then carry on: 1187 / 405

Advancing to step 8:
1187 divided by 405 is 2 with a remainder of 377.
The next digit of our result is 2. 
Result so far: 30702.0
Deduct 810 from 1187 and we're left with 377.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3770, and continue the process.

On to step 9:
3770 divided by 405 is 9 with a remainder of 125.
Use 9 as the next digit of our solution. 
Result so far: 30702.9
If we subtract 3645 from 3770, we get 125.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1250, and continue the process.

Let's proceed to step 10:
If we divide 1250 by 405, we get 3 and a remainder of 35.
Put 3 as the next digit of the answer. 
Result so far: 30702.93
If we subtract 1215 from 1250, we get 35.
Since there are no more digits in the dividend, we add a zero to the remainder making it 350, and continue the process.

Let's proceed to step 11:
The number 405 fits into 350 0 times, leaving a remainder of 350.
The next digit of our result is 0. 
Result so far: 30702.93
Subtracting 0 from 350 leaves us with 350.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3500, and continue the process.

Advancing to step 12:
If we divide 3500 by 405, we get 8 and a remainder of 260.
Write down 8 as next digit of the result. 
Result so far: 30702.9308
Subtract 3240 from 3500 to get 260.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2600, and continue the process.

Going ahead to step 13:
405 goes into 2600 6 times with a remainder of 170.
The next digit of our result is 6. 
Result so far: 30702.93086
Subtract 2430 from 2600 to get 170.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1700, and continue the process.

Let's proceed to step 14:
When dividing 1700 by 405, we get 4 with a remainder of 80.
The next digit of our result is 4. 
Result so far: 30702.930864
Deduct 1620 from 1700 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Step 15:
The number 405 fits into 800 1 times, leaving a remainder of 395.
Put 1 as the next digit of the answer. 
Result so far: 30702.9308641
Deduct 405 from 800 and we're left with 395.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3950, and continue the process.

Advancing to step 16:
The number 405 fits into 3950 9 times, leaving a remainder of 305.
Use 9 as the next digit of our solution. 
Result so far: 30702.93086419
If we take 3645 away from 3950, we end up with 305.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

After the division, we end up with 30702.93086419 and a remainder of 3.05e-07.