We look at the division of 8687718 by 390 
The aim is to understand the frequency of 390 in 8687718.

Let's proceed to step 1:
8 divided by 390 is 0 with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 8 and we're left with 8.
Fetch the next digit (6) from the dividend, attach it to 8 and continue: 86 / 390

Let's proceed to step 2:
390 goes into 86 0 times with a remainder of 86.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 86, we end up with 86.
Include the next digit (8) from the dividend after 86, then repeat: 868 / 390

Let's proceed to step 3:
390 goes into 868 2 times with a remainder of 88.
The next digit of our result is 2. 
Result so far: 2.0
If we subtract 780 from 868, we get 88.
Fetch the next digit (7) from the dividend, attach it to 88 and continue: 887 / 390

Advancing to step 4:
The number 390 fits into 887 2 times, leaving a remainder of 107.
The next digit of our result is 2. 
Result so far: 22.0
Subtract 780 from 887 to get 107.
Grab the next digit (7) from the dividend, add it to 107, then carry on: 1077 / 390

On to step 5:
The number 390 fits into 1077 2 times, leaving a remainder of 297.
The next digit of our result is 2. 
Result so far: 222.0
The remainder is 297 after subtracting 780 from 1077.
Take the next digit (1) from the dividend and append it to 297, then repeat: 2971 / 390

Step 6:
When dividing 2971 by 390, we get 7 with a remainder of 241.
Put 7 as the next digit of the answer. 
Result so far: 2227.0
If we take 2730 away from 2971, we end up with 241.
Fetch the next digit (8) from the dividend, attach it to 241 and continue: 2418 / 390

Let's proceed to step 7:
2418 divided by 390 is 6 with a remainder of 78.
The number 6 becomes the next digit in our result. 
Result so far: 22276.0
Deduct 2340 from 2418 and we're left with 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

On to step 8:
If we divide 780 by 390, we get 2 and a remainder of 0.
The next digit of our result is 2. 
Result so far: 22276.2
Deduct 780 from 780 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 9:
If we divide 0 by 390, we get 0 and a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 22276.2
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Step 10:
390 goes into 0 0 times with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 22276.2
If we take 0 away from 0, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The final result is 22276.2 with a remainder of 0.0.