We look at the division of 7017887 by 561 
The aim is to understand the frequency of 561 in 7017887.

On to step 1:
When dividing 7 by 561, we get 0 with a remainder of 7.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 7 after subtracting 0 from 7.
Include the next digit (0) from the dividend after 7, then repeat: 70 / 561

Let's proceed to step 2:
If we divide 70 by 561, we get 0 and a remainder of 70.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 70, we end up with 70.
Bring next digit (1) of the dividend behind the 70 and repeat the process: 701 / 561

Moving on to step 3:
If we divide 701 by 561, we get 1 and a remainder of 140.
Put 1 as the next digit of the answer. 
Result so far: 1.0
Subtracting 561 from 701 leaves us with 140.
Take the next digit (7) from the dividend and append it to 140, then repeat: 1407 / 561

Step 4:
561 goes into 1407 2 times with a remainder of 285.
The next digit of our result is 2. 
Result so far: 12.0
Subtracting 1122 from 1407 leaves us with 285.
Append the next digit (8) from the dividend to 285 and continue with: 2858 / 561

Advancing to step 5:
The number 561 fits into 2858 5 times, leaving a remainder of 53.
The number 5 becomes the next digit in our result. 
Result so far: 125.0
If we take 2805 away from 2858, we end up with 53.
Bring next digit (8) of the dividend behind the 53 and repeat the process: 538 / 561

Advancing to step 6:
538 divided by 561 is 0 with a remainder of 538.
Record the quotient 0 as the next digit in the result. 
Result so far: 1250.0
Subtract 0 from 538 to get 538.
Take the next digit (7) from the dividend and append it to 538, then repeat: 5387 / 561

Step 7:
561 goes into 5387 9 times with a remainder of 338.
Use 9 as the next digit of our solution. 
Result so far: 12509.0
Deduct 5049 from 5387 and we're left with 338.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3380, and continue the process.

Moving on to step 8:
If we divide 3380 by 561, we get 6 and a remainder of 14.
The number 6 becomes the next digit in our result. 
Result so far: 12509.6
Subtract 3366 from 3380 to get 14.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

On to step 9:
561 goes into 140 0 times with a remainder of 140.
Use 0 as the next digit of our solution. 
Result so far: 12509.6
If we take 0 away from 140, we end up with 140.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1400, and continue the process.

Going ahead to step 10:
561 goes into 1400 2 times with a remainder of 278.
Use 2 as the next digit of our solution. 
Result so far: 12509.602
If we subtract 1122 from 1400, we get 278.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2780, and continue the process.

Advancing to step 11:
If we divide 2780 by 561, we get 4 and a remainder of 536.
The next digit of our result is 4. 
Result so far: 12509.6024
If we take 2244 away from 2780, we end up with 536.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5360, and continue the process.

Advancing to step 12:
If we divide 5360 by 561, we get 9 and a remainder of 311.
The number 9 becomes the next digit in our result. 
Result so far: 12509.60249
The remainder is 311 after subtracting 5049 from 5360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3110, and continue the process.

Let's proceed to step 13:
561 goes into 3110 5 times with a remainder of 305.
Use 5 as the next digit of our solution. 
Result so far: 12509.602495
Subtract 2805 from 3110 to get 305.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

Step 14:
561 can be fit into 3050 5 times, resulting in a remainder of 245.
Record the quotient 5 as the next digit in the result. 
Result so far: 12509.6024955
Deduct 2805 from 3050 and we're left with 245.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2450, and continue the process.

In conclusion, the division gives 12509.6024955 with a balance of 2.45e-06.