We're dividing 15303942 by 561 
The aim is to understand the frequency of 561 in 15303942.

Going ahead to step 1:
561 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 1, we end up with 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 561

Let's proceed to step 2:
When dividing 15 by 561, we get 0 with a remainder of 15.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 15 leaves us with 15.
Include the next digit (3) from the dividend after 15, then repeat: 153 / 561

Going ahead to step 3:
The number 561 fits into 153 0 times, leaving a remainder of 153.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 153 and we're left with 153.
Append the next digit (0) from the dividend to 153 and continue with: 1530 / 561

Going ahead to step 4:
The number 561 fits into 1530 2 times, leaving a remainder of 408.
Write down 2 as next digit of the result. 
Result so far: 2.0
Subtract 1122 from 1530 to get 408.
Include the next digit (3) from the dividend after 408, then repeat: 4083 / 561

Let's proceed to step 5:
When dividing 4083 by 561, we get 7 with a remainder of 156.
Write down 7 as next digit of the result. 
Result so far: 27.0
Deduct 3927 from 4083 and we're left with 156.
Include the next digit (9) from the dividend after 156, then repeat: 1569 / 561

Let's proceed to step 6:
1569 divided by 561 is 2 with a remainder of 447.
Use 2 as the next digit of our solution. 
Result so far: 272.0
Deduct 1122 from 1569 and we're left with 447.
Fetch the next digit (4) from the dividend, attach it to 447 and continue: 4474 / 561

On to step 7:
The number 561 fits into 4474 7 times, leaving a remainder of 547.
Write down 7 as next digit of the result. 
Result so far: 2727.0
If we subtract 3927 from 4474, we get 547.
Bring next digit (2) of the dividend behind the 547 and repeat the process: 5472 / 561

Advancing to step 8:
561 can be fit into 5472 9 times, resulting in a remainder of 423.
Use 9 as the next digit of our solution. 
Result so far: 27279.0
If we take 5049 away from 5472, we end up with 423.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4230, and continue the process.

On to step 9:
If we divide 4230 by 561, we get 7 and a remainder of 303.
Record the quotient 7 as the next digit in the result. 
Result so far: 27279.7
Deduct 3927 from 4230 and we're left with 303.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3030, and continue the process.

On to step 10:
When dividing 3030 by 561, we get 5 with a remainder of 225.
Record the quotient 5 as the next digit in the result. 
Result so far: 27279.75
Deduct 2805 from 3030 and we're left with 225.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2250, and continue the process.

Step 11:
The number 561 fits into 2250 4 times, leaving a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 27279.754
If we subtract 2244 from 2250, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Let's proceed to step 12:
60 divided by 561 is 0 with a remainder of 60.
The number 0 becomes the next digit in our result. 
Result so far: 27279.754
Subtract 0 from 60 to get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Moving on to step 13:
If we divide 600 by 561, we get 1 and a remainder of 39.
Use 1 as the next digit of our solution. 
Result so far: 27279.75401
Subtract 561 from 600 to get 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

Moving on to step 14:
When dividing 390 by 561, we get 0 with a remainder of 390.
The next digit of our result is 0. 
Result so far: 27279.75401
If we take 0 away from 390, we end up with 390.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3900, and continue the process.

Advancing to step 15:
The number 561 fits into 3900 6 times, leaving a remainder of 534.
Use 6 as the next digit of our solution. 
Result so far: 27279.7540106
Subtract 3366 from 3900 to get 534.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5340, and continue the process.

Let's proceed to step 16:
561 goes into 5340 9 times with a remainder of 291.
Record the quotient 9 as the next digit in the result. 
Result so far: 27279.75401069
Subtract 5049 from 5340 to get 291.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2910, and continue the process.

The final result is 27279.75401069 with a remainder of 2.91e-07.