We're dividing 13212307 by 861 
The aim is to understand the frequency of 861 in 13212307.

Step 1:
If we divide 1 by 861, we get 0 and a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 1 to get 1.
Include the next digit (3) from the dividend after 1, then repeat: 13 / 861

Step 2:
When dividing 13 by 861, we get 0 with a remainder of 13.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 13 leaves us with 13.
Include the next digit (2) from the dividend after 13, then repeat: 132 / 861

Moving on to step 3:
The number 861 fits into 132 0 times, leaving a remainder of 132.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 132, we get 132.
Take the next digit (1) from the dividend and append it to 132, then repeat: 1321 / 861

Let's proceed to step 4:
The number 861 fits into 1321 1 times, leaving a remainder of 460.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Deduct 861 from 1321 and we're left with 460.
Fetch the next digit (2) from the dividend, attach it to 460 and continue: 4602 / 861

On to step 5:
When dividing 4602 by 861, we get 5 with a remainder of 297.
Record the quotient 5 as the next digit in the result. 
Result so far: 15.0
The remainder is 297 after subtracting 4305 from 4602.
Bring next digit (3) of the dividend behind the 297 and repeat the process: 2973 / 861

On to step 6:
861 can be fit into 2973 3 times, resulting in a remainder of 390.
Record the quotient 3 as the next digit in the result. 
Result so far: 153.0
If we subtract 2583 from 2973, we get 390.
Fetch the next digit (0) from the dividend, attach it to 390 and continue: 3900 / 861

Let's proceed to step 7:
When dividing 3900 by 861, we get 4 with a remainder of 456.
Write down 4 as next digit of the result. 
Result so far: 1534.0
If we take 3444 away from 3900, we end up with 456.
Fetch the next digit (7) from the dividend, attach it to 456 and continue: 4567 / 861

Advancing to step 8:
The number 861 fits into 4567 5 times, leaving a remainder of 262.
The next digit of our result is 5. 
Result so far: 15345.0
If we take 4305 away from 4567, we end up with 262.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2620, and continue the process.

Step 9:
The number 861 fits into 2620 3 times, leaving a remainder of 37.
The number 3 becomes the next digit in our result. 
Result so far: 15345.3
If we take 2583 away from 2620, we end up with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

On to step 10:
861 can be fit into 370 0 times, resulting in a remainder of 370.
The number 0 becomes the next digit in our result. 
Result so far: 15345.3
If we take 0 away from 370, we end up with 370.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3700, and continue the process.

Let's proceed to step 11:
The number 861 fits into 3700 4 times, leaving a remainder of 256.
Record the quotient 4 as the next digit in the result. 
Result so far: 15345.304
If we subtract 3444 from 3700, we get 256.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2560, and continue the process.

Moving on to step 12:
2560 divided by 861 is 2 with a remainder of 838.
Record the quotient 2 as the next digit in the result. 
Result so far: 15345.3042
The remainder is 838 after subtracting 1722 from 2560.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8380, and continue the process.

On to step 13:
The number 861 fits into 8380 9 times, leaving a remainder of 631.
The number 9 becomes the next digit in our result. 
Result so far: 15345.30429
If we subtract 7749 from 8380, we get 631.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6310, and continue the process.

Going ahead to step 14:
861 can be fit into 6310 7 times, resulting in a remainder of 283.
The next digit of our result is 7. 
Result so far: 15345.304297
Deduct 6027 from 6310 and we're left with 283.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2830, and continue the process.

Going ahead to step 15:
2830 divided by 861 is 3 with a remainder of 247.
The number 3 becomes the next digit in our result. 
Result so far: 15345.3042973
If we subtract 2583 from 2830, we get 247.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2470, and continue the process.

Let's proceed to step 16:
The number 861 fits into 2470 2 times, leaving a remainder of 748.
Write down 2 as next digit of the result. 
Result so far: 15345.30429732
Deduct 1722 from 2470 and we're left with 748.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7480, and continue the process.

The final result is 15345.30429732 with a remainder of 7.48e-07.